Evaluation of Composted Poultry Litter Use in Horticulture 
 
by 
 
Stephen Christopher Marble 
 
 
 
 
A thesis submitted to the Graduate Faculty of  
Auburn University 
in partial fulfillment of the 
requirements for the Degree of 
Master of Science 
 
Auburn, Alabama  
December 18, 2009 
 
 
 
 
Keywords: compost, poultry litter, landscape, container production,  
ornamental, fertilizer source 
 
 
Copyright 2009 by Stephen Christopher Marble 
 
 
Approved by 
 
Jeff L. Sibley, Co-Chair, Professor of Horticulture 
Charles H. Gilliam, Co-Chair, Professor of Horticulture 
Henry Allen Torbert, III, Research Leader/Soil Scientist 
 USDA-ARS National Soil Dynamics Lab
ii 
 
 
 
 
 
 
                                                     Abstract 
 
The U.S. poultry and egg industry is valued at billions of dollars in gross farm 
receipts and employs hundreds of thousands of people. A Survey by the United States 
Department of Agriculture in 2008 revealed that in Alabama alone, the poultry industry 
generates over $2 billion in gross farm receipts and employs over 78,000 people.   Over 
the past several decades the poultry industry has expanded exponentially.  With this 
growth comes the problem of poultry waste disposal.  It is estimated that 16.6 million 
tons of poultry litter is produced in the United States each year and 2 million tons of litter 
is generated by the poultry and egg industry each year in Alabama alone.  Poultry farmers 
face the challenge of storing this material, which occupies valuable space on their farms.  
Often disposal can be costly, and there are also many environmental problems which 
arise when large amounts of poultry litter are mishandled.   Poultry producers must find a 
way to dispose of this manure in a way that is both economically sound and 
environmentally safe.  The objective of this research was to evaluate the use of 
composted poultry litter and determine what areas of the horticulture industry that CPL 
can be the most beneficial.  Results from these studies may help determine how 
composted poultry litter can be used beneficially in the landscape and container nursery 
industries while providing poultry producers an environmentally sound means of waste 
disposal.   Two experiments were conducted evaluating a variety of commonly grown 
iii 
 
nursery crops for growth in alternative wood based substrates.  Whole Tree (WT) and 
Clean Chip Residual (CCR) are potential new nursery substrates that are by-products of 
the forestry industry containing high wood content.  Initial immobilization of nitrogen is 
one limitation of these new substrates; however the addition of composted poultry litter 
(CPL) to substrates containing high wood content could balance initial nitrogen 
immobilization and provide an inexpensive fertilizer source for growers.  This study 
evaluated the growth of five woody nursery crops being grown in WT, CCR, and 
pinebark (PB) with the addition of CPL or peat as a substrate amendment.   Results 
indicate that woody nursery crops can be grown successfully in WT and CCR substrates 
6:1 (v:v) with CPL.  Use of CPL in WT and CCR substrates provides an alternative to 
traditional PB plus peat based combinations in container plant production while 
providing poultry producers an environmentally sound means of waste disposal. 
Three additional experiments involved the application of CPL to landscape annual beds 
and the evaluation of plant performance as well as non-point water pollution potential.  
The objective of these studies was to evaluate composted poultry litter as a fertilizer 
source for bedding plants at various rates in comparison with commercially available 
inorganic fertilizers for three commonly used landscape annual bedding species, ?Quartz 
Scarlet? verbena, ?Celebrity Red? petunia, and Dusty Miller.  Raised beds were 
constructed and  before planting 10 treatments were applied: Peafowl garden grade 
fertilizer 13N-5.6P-10.9K (13-13-13) at rates of 4.9 g N/m
2 
(1 lb N/1000 ft
2
) and 9.8 g 
N/m
2 
(2 lb N/1000 ft
2
), Polyon 13N-5.6P-10.9K (13-13-13) at rates of 4.9 g N/m
2 
(1 lb 
N/1000 ft
2
) and 9.8 g N/m
2 
(2 lb N/1000 ft
2
) and composted poultry litter at rates of 4.9 g 
iv 
 
N/m
2 
(1 lb N/1000 ft
2
), 9.8 g N/m
2 
(2 lb N/1000 ft
2
), 19.6 g N/m
2 
(4 lb N/1000 ft
2
), 29.4 g 
N/m
2 
(6 lb N/1000 ft
2
), 39.2 g N/m
2 
(8 lb N/1000 ft
2
), and 49 g N/m
2 
(10 lb N/1000 ft
2
).  
A control group receiving no fertilizer application was also maintained.  Soil water 
leachates were collected using suction cup lysimeters 0.6 m (2ft) long and 5.1 cm (2 in) 
in diameter with a ceramic cap 7.6 cm (3 in) long and 5.1 cm (2 in) wide.  Results from 
these experiments provides evidence that composted poultry litter could be used as a 
substitute for conventional inorganic fertilizers when used at the same nitrogen rate and 
may also be applied at much higher rates than inorganic fertilizers resulting in plants with 
greater size while minimizing negative environmental impacts.  
v 
 
 
 
 
Acknowledgments 
 
I would like to thank Dr. Sibley for the support and guidance he has given me 
over the past two years, for allowing me to work on this project, and his exceptional help 
on the preparation of this manuscript.  I would also like to thank Dr. Allen Torbert for 
lending guidance and giving advice while serving on my advisory committee.  I would 
also like to thank Dr. Glenn Fain and John Olive for their support and help during the 
completion of this research.  I would especially like to thank Dr. Charles Gilliam for his 
help during this research and the preparation of this manuscript.  Throughout my time in 
graduate school, Dr. Gilliam has been a mentor and a friend, all while providing me with 
countless ?opportunities? along the way. 
 I want to thank Jeremy Pickens, Daniel Wells, Matthew Wilson, B.J. Brymer and 
Tyler Monday for their friendship all of the help they provided in the field and in the 
classroom.  Without their help this manuscript would not be possible.  I would also like to 
thank Albert Van Hoogmoed and Anna-Marie Murphy for their help in the collection and 
entering of data.   
 I want to also thank my parents for their love, support, and for encouraging me to 
pursue all of my academic goals.  They have given me the confidence to take on all of 
life?s challenges and are always there for me whenever I need them.  Most importantly, I 
would like to thank my heavenly Father for guiding me in every aspect of my life.
 
vi 
 
Table of Contents 
Abstract ............................................................................................................................... ii 
Acknowledgments................................................................................................................v 
List of Tables ................................................................................................................... viii 
I. Introduction and Literature Review ..................................................................................1 
      Introduction ....................................................................................................................1 
      Literature Cited ............................................................................................................22 
II. Evaluation of Composted Poultry Litter as a Substrate Amendment for WholeTree,  
     Clean Chip Residual, and Pinebark for Container Grown Nursery Woody  
     Ornamentals ..................................................................................................................31 
      Abstract ........................................................................................................................31 
      Introduction ..................................................................................................................31                         
 Materials and Methods .................................................................................................35 
  Results .........................................................................................................................38 
       Discussion ...................................................................................................................46 
  Literature Cited ............................................................................................................48 
III. Application of Composted Poultry Litter as a Fertilizer for Landscape Use ...............64 
       Abstract?????????????????????????????...64 
       Introduction???????????????????.?????????65
      Materials and Methods????????????????????????69 
 
vii 
 
       Results??????????????????????????????.73
       Discussion ...................................................................................................................83 
       Literature Cited?????????????????????????.......89 
IV. Final Discussion...........................................................................................................64 
   
 
viii 
 
List of Tables 
    Chapter II:                                                                                                                              
 Table 1.1 Experiment 1: Solution pH and electrical conductivity (EC) of substrates ...52 
 Table 1.2 Experiment 1: Influence of substrate composition on growth indices at 120 
                 and 340 days after transplanting .....................................................................53 
    Table 1.3 Experiment 1: Influence of substrate composition on foliar color ratings at                       
                    60 and 120 days after transplanting ...............................................................54 
    Table 1.4 Experiment 1: Influence of substrate composition on root ratings and  
                     shrinkage .......................................................................................................55 
    Table 1.5 Experiment 1: Tissue nutrient content of Ternstroemia gymnanthera ..........56 
    Table 2.1 Experiment 2: Physical properties of whole tree, pinebark, and clean chip  
                   residual based substrates .............................................................................57 
    Table 2.2 Particle size analysis of substrates .................................................................58 
    Table 2.3 Experiment 2: Solution pH and electrical conductivity (EC) of substrates ...59 
    Table 2.4 Experiment 2: Influence of substrate composition on growth indices at 60  
                     and 390 days after transplanting ...................................................................60 
    Table 2.5 Experiment 2: Influence of substrate composition on foliar color ratings at  
                    60, 120, and 390 DAT....................................................................................61    
   Table 2.6 Experiment 2: Influence of substrate composition on root ratings .................62 
   Table 2.7 Experiment 2: Influence of substrate composition on shrinkage ....................63 
 
ix 
 
 Chapter III: 
Table 1.1 Effect of fertilizer on growth indices and shoot dry weights of ?Celebrity   
                   Red? Petunia and ?Quartz Scarlet? verbena .....................................................93 
Table 1.2 Effect of fertilizers on leaf chlorophyll content of ?Celebrity Red? petunia and   
                  ?Quartz Scarlet? verbena ..................................................................................94  
Table 1.3 Effect of fertilizer on tissue nutrient content of Petunia spp. ?Celebrity Red?,  
                 Experiment 1 .....................................................................................................95 
 Table 1.4 Effect of fertilizer on tissue nutrient content of Verbena hybrida ?Quartz 
                Scarlet?, Experiment 1 .......................................................................................96 
Table 1.5 Effect of fertilizers on N in soil water, Experiment 1 ........................................97 
Table 1.6 Effect of fertilizers on pH and electrical conductivity of soil water,  
               Experiment 1 .......................................................................................................98 
Table 2.1 Effect of fertilizer on growth indices and shoot dry weights of ?Celebrity Red?  
               Petunia and ?Quartz Scarlet? verbena .................................................................99 
Table 2.2 Effect of fertilizers on leaf chlorophyll content of ?Celebrity Red? petunia and   
               ?Quartz Scarlet?verbena ....................................................................................100 
Table 2.3 Effect of fertilizer on tissue nutrient content of Petunia spp. ?Celebrity Red?,  
                 Experiment 2 ...................................................................................................101 
Table 2.4 Effect of fertilizer on tissue nutrient content of Verbena hybrida ?Quartz  
                Scarlet?, Experiment 2 .....................................................................................102 
Table 2.5 Effect of fertilizers on N in soil water, Experiment 2 ......................................103 
Table 2.6 Effect of fertilizers on pH and electrical conductivity of soil water, Experiment   
                2........................................................................................................................104 
 
x 
 
Table 3.1 Effect of fertilizers on growth indices and shoot dry weights of ?Celebrity Red?   
                petunia and dusty miller ...................................................................................105 
Table 3.2 Effect of fertilizers on leaf chlorophyll content of ?Celebrity Red? petunia and     
            dusty miller ..........................................................................................................106 
Table 3.3 Effect of fertilizer on tissue nutrient content of Petunia spp. ?Celebrity Red?,   
            Experiment 3 ....................................................................................................107 
Table 3.4 Effect of fertilizer on tissue nutrient content of Senecio cineraria (Dusty Miller),  
                Experiment 3 ....................................................................................................108 
Table 3.5 Effect of fertilizer on N in soil water, Experiment 3 .......................................109 
Table 3.6 Effect of fertilizers on pH and electrical conductivity of soil water, Experiment     
                3........................................................................................................................110 
 
    
 
1 
 
 
 
 
 
CHAPTER I 
 
Introduction and Literature Review 
 
The U.S. poultry and egg industry is valued at billions of dollars in gross farm 
receipts and employs hundreds of thousands of people.  In Alabama alone, the poultry 
industry generates over $2 billion in gross farm receipts and employs over 78,000 people 
(USDA, 2008).  Over the past several decades the poultry industry has expanded 
exponentially.  Increasing demand for low cholesterol meat products along with the 
recent cost saving changes in the farming industry from small family farms to large 
commercial farming practices have attributed to this expansion (Moore et al., 1996).  
Combined value of production from broilers, eggs, turkeys, and the value of sales 
from chickens in 2007 was $31.9 billion, up 24% from the $25.8 billion in 2006 (USDA, 
2008).  Poultry production in the United States is predominately concentrated in the mid 
south region with Arkansas, Georgia, North Carolina, and Alabama accounting for 40 
percent of the nation?s poultry industry (Moore et al. 1995).  As a nation the U.S. 
produces 8.9 billion birds annually with Alabama currently third in production with 
11.9% (1.1 billion birds) of U.S. totals (AAS, 2007). A conservative estimate of 16.6 
million tons of poultry litter is produced in the United States each year and 2 million tons 
of litter is generated by the poultry and egg industry each year in Alabama alone 
(Edwards et al., 1995).  Poultry farmers face the challenge of storing this material, which 
 
2 
 
occupies valuable space on their farms.  Often disposal can be costly, and there are also 
many environmental problems which arise when large amounts of poultry litter are 
mishandled (Moore et al., 1995).  Poultry producers must find a way to dispose of this 
manure in a way that is both economically sound and environmentally safe. 
 The most common type of waste produced from poultry operations is poultry litter 
or broiler litter, which includes all floor type birds such as broiler, pullets, and floor 
layers.  Some type of bedding or litter material is used on the floors of the poultry houses 
such as pinebark, sawdust, straw, paper, peanut or rice hulls, etc, depending upon locality 
(Moore et al., 1996).  Waste from the poultry production systems includes a mixture of 
excreta (manure) and the bedding material listed above.  During the production cycle 
accumulating manure becomes mixed with litter (bedding material) and at the end of the 
cycle both are removed together (Kelleher et al., 2002).   The term poultry litter refers to 
the bedding material used during the poultry production cycle (materials such as straw, 
sawdust, wood shavings, shredded paper, and peanut or rice hulls).  When manure is 
mixed with bedding material and removed from poultry houses it is referred to as poultry 
litter or broiler litter.   
Some poultry production systems result in liquid poultry manures (those 
containing less than 150 g of dry matter kg
-1
).  Liquid poultry manures are usually limited 
to laying-hen operations.  Caged layer manure is free from litter material and generally 
contains higher moisture content than manure from broiler houses.  All types of manure 
will contain feathers, wasted food, and dead birds (Mitchell et al., 1995).  Moisture 
content can range from 20-75% depending on moisture levels, temperature, amount and 
 
3 
 
kind of litter material used, and the conditions under which the litter was stored.  Typical 
poultry litter will have the following nutrient ranges: Nitrogen from 2.1 to 6%, 
Phosphorus from 1.4 to 9%, Potassium from 0.8 to 6.2%, Calcium from 0.8 to 6.1%, 
Magnesium from 0.2 to 2.1%, and sulfur from 0.1 to 0.8%, on a dry-weight basis 
(Mitchell et al., 1995).  Most litter is spread raw, before composting, because of the need 
to dispose of the manure quickly and the time constraints of fertilizer applications due to 
the time consuming process of composting (Mitchell et al., 1995).  For poultry litter to be 
used in a non-agronomic setting, composting would be necessary to ensure a stable 
fertilizer source that would have little odor or pathogen concerns. 
Historically, poultry wastes have been used as a source of fertilizer and soil 
amendment in agronomic row cropping systems.  Land application offers the best 
solution to managing large amounts of poultry litter (Moore et al., 1996).  Excluding the 
small amounts used in animal feed, or as an alternative fuel source, almost ninety-percent 
of all poultry litter produced is applied to agricultural land, usually no more than a few 
miles from where litter is produced (Moore et al., 1995).  This is usually a viable option 
since the majority of time poultry manure is often produced in areas where it can be 
utilized on neighboring farms to fertilize hay fields and pastures (Sloan et al., 1996).  In a 
study conducted in 1995, researchers projected that in Alabama where almost 2 million 
tons of litter is produced, if properly handled and utilized, the nutrients in this manure 
could fertilize every acre of corn, wheat, and sorghum produced in the state, or 323,748 
hectares (800,00 acres) of bermudagrass sod production (Mitchell et al., 1995).   
 
4 
 
Handling systems for poultry litter encompass all the operations for removing 
manure from the poultry houses, pre-treating, and transporting the manure to the field 
where it will be spread by spreading equipment (Moore et al., 1996).  Upon removal from 
the poultry house, poultry litter may be immediately spread or temporarily stored; both 
posing environmental hazards.  When spread on agricultural land, poultry litter is usually 
applied based solely on nitrogen content.  Poultry litter nitrogen (N) to phosphorus (P) 
concentration is roughly 2:1, and long term applications to land can cause an 
accumulation of phosphorous.  In one study, less than one half of the phosphorus 
contained in poultry litter was removed by Bermuda grass sod (Brink et al., 2004). Over 
long periods of repeated application there have been pH increases in soil and high 
phosphorus concentrations, regardless of the crops efficiency to use phosphorus (Grichar 
et al., 2005).    
Over-application of poultry litter can lead to accumulation of nutrients in water 
bodies.  Phosphorus is usually the limiting nutrient for eutrophication in fresh water 
bodies, rivers, lakes, and streams (Moore and Edwards, 2005).  In 1996, the 
Environmental Protection Agency suggested that eutrophication was the main cause of 
impaired water sources.  In northwestern Arkansas and northeastern Oklahoma, 
researchers studied several river systems experiencing problems due to excess 
phosphorus and nitrogen pollution from point and non-point sources from over use of 
manure as agronomic fertilizer.  Another problem accentuated by over application of 
poultry litter near water bodies is algal blooms.  Algal blooms cause taste and odor 
problems in drinking water and can be potentially harmful to one?s health.  Increased 
 
5 
 
aquatic plant growth can have many negative environmental impacts, resulting in fish 
kills, water pH problems (Moore and Edwards, 2005).  Excessive application of poultry 
litter in cropping systems can also result in nitrate (N0
3
) contamination of groundwater.  
High levels of N0
3
 in drinking water have been found to cause methaemoglobinaemia 
(blue baby syndrome), cancers, and respiratory illnesses in humans and fetal abortions in 
livestock (Bitzer and Simms, 1998; Stevenson, 1986).  Another concern with land 
application of poultry litter is the potential spread of dangerous pathogens and bacteria 
(Kelleher et al., 2002).  Regulatory mandates have increased the demand for Best 
Management Practices (BMP?s) that will reduce nutrient leaching on water sheds affected 
by excess leaching of phosphorus and nitrogen from manure holding and storage areas, 
and after field application (Veitor et al., 2001).  Disposal of organic waste products such 
as poultry litter has become more and more difficult for poultry producers because of 
increased awareness of the potentially harmful effects that these manures can have on 
ground and surface water supplies (Allen et al., 1994). 
Due to increased environmental awareness, poultry litter is coming under strict 
new state and federal regulations concerning disposal methods with respect to non-point 
source pollution and other environmental concerns.  In 1972, the United States passed the 
Clean Water Act (CWA), which placed restrictions on the amount of litter and other 
pollutants that could be land applied.  The CWA established the basic structure for 
regulating discharges of pollutants into the waters of the United States and placed 
regulating quality standards for surface waters.  Initially, the CWA had little impact on 
poultry producers and placed few limitations on disposal practices.  However, in 2003 the 
 
6 
 
EPA implemented new stricter regulations that would force large operations to manage 
their manure according to a nutrient management plan.  Farmers with the largest 
operations are forced to acquire permits and new limits were placed on the amount of 
litter that could be spread via land application (EPA, 2003).  Finding ways to properly 
manage the litter and dispose of it properly is essential so that the valuable nutrients in 
the litter can be utilized without causing negative environmental impacts.   
Poultry manure contains a significant concentration of organic nitrogen due to the 
presence of high levels of protein and amino acids.  Of the nitrogen in fresh manure, 60-
80% is typically in organic form, such as urea and protein.  Depending on environmental 
conditions, a large percentage of this organic nitrogen (40-90%) is converted to ammonia 
within a year.  Ammonia exists as either gas (NH
3
) or in an ionized state (NH
4
) which is 
water soluable.  NH
3
 gas can be lost to the atmosphere while NH
4
 can be transformed by 
microorganisms to nitrate (process called nitrification).  During anaerobic digestion of 
poultry litter, the concentration of ammonia-nitrogen rises.  Some of the anaerobic 
microorganisms can use ammonium ions, but an excess of ammonium can inhibit the 
destruction of organic compounds.  Therefore, the presence of ammonium ions 
contributes to high pH and leads to handling, storage, and disposal issues.  Minimization 
of ammonia content is desired for any treatment of poultry litter.  Proper composting can 
eliminate some of these concerns and decrease ammonia content (Kelleher et al., 2002). 
  Poultry litter is sometimes composted before incorporation into potting mixes, 
landscape beds, or spreading it on crop lands and pastures.  Composting is the aerobic 
degradation of biodegradable organic waste and is an effective and inexpensive way to 
 
7 
 
stabilize organic matter (Kelleher et al., 2002; Tiquia and Tam, 2000).  Composting 
methods include in-vessel composting with the use of rotating drums, turned windrows, 
forced aeration piles, static piles, and other means (Brymer, 2008).  Organic materials are 
decomposed in an accelerated aerobic process through oxidation of carbon by microbial 
activity (Fritsch and Collins, 1993).  The end result is a stable organic product which has 
been reported to improve soil quality, reduces bulk density, increases soil cation 
exchange capacity, and enhances populations of soil microorganisms (Fritsch and 
Collins, 1993).  After manure has been composted, it has a more stable form of nutrients 
and is easier to transport and spread.  Composted poultry litter is generally odorless, 
pathogen free, and fine-textured with a low moisture content making it easier to handle 
and can be used as an organic fertilizer in most situations (Kelleher et al, 2002).  The 
main disadvantage of composting poultry litter is a decrease in total nitrogen and other 
nutrients during composting.   Nitrification and de-nitrification, which poultry litter 
undergoes during composting, has been found to result in losses of 21 to 77% of the 
nitrogen nutrient concentration of the litter after composting (Tiquia and Tam, 2000).    
Equipment costs associated with composting such as windrow turners, in-vessel 
digesters, etc., increased labor costs, odor problems, and available land needed to store 
the poultry litter until composting can be completed are also cited as disadvantages 
(Sweeten, 1988).  While nutrient losses will occur with composting, the ease of handling, 
odor-reduction, stabilization of nutrients, improvements in storage and handling, as well 
as pathogen reduction, make composted poultry litter a more desirable product in almost 
all situations.   
 
8 
 
Brymer (2008) evaluated composting methods of poultry litter for use in the green 
industry.  In-vessel composting was compared to windrow composting in respect to 
bacteria levels, container leachate, weed germination, and plant growth.  Both methods of 
composting resulted in compost with safe bacteria levels for human use.  In one study 
Impatiens wallerana ?Fanfare? was grown in substrates containing equal amounts of 
either in-vessel composted poultry litter (IVPL) or windrow composted poultry litter 
(WRPL).  Results indicate that WRPL outperformed the IVPL in plant dry weights and 
growth indices.  Substrate leachates from WRPL were also more suitable for growing 
containerized crops than IVPL.  In an additional study, Brymer evaluated Hemerocallis 
spp. ?Pardon Me? when grown in either IVPL or WRPL.  Again, WRPL outperformed 
IVPL based upon plant growth indices and dry weights.  Results also indicate that both 
methods are equally suited at eradicating potential weed seed present during the 
composting process (Brymer, 2008).  Furthermore, based upon results from these studies, 
IVPL may not be suitable for production of ornamental crops without pre-plant leaching 
of salts.  
For many years poultry farmers predominately disposed of their manure and 
waste by spreading it on crop and pastureland.  Producers could sell their manure to area 
farmers as an inexpensive fertilizer source ($8 per ton, or at the cost of hauling in some 
instances).  New regulations are placing limits on this practice but a fair amount of litter 
can still be applied; however, management of available lands for application is now 
becoming a problem.  As populations continue to grow, rural areas are declining in size 
as cities are expanding to meet population needs.  As a result, there are fewer acres of 
 
9 
 
agricultural land for spreading this manure (Wolfe and Humphries, 2007).  Expansion of 
cities and population increases could present a new avenue for poultry litter disposal in 
the landscape and soilless potting media industry.  The horticulture industry is now a fast 
growing sector in agriculture, with more and more landscape and nursery operations in 
business, poultry producers are turning to the green industry as a means of disposing 
excess manure.  Currently research is being conducted to find alternative uses for 
composted poultry litter in these different agricultural sectors and to establish in what 
areas poultry litter could provide the best economic and environmental benefit. 
  Considering the high nutrient content of poultry litter and the accessibility of the 
product, especially in the intense production areas of the southeastern United States, 
horticulture professionals, farmers, and turfgrass managers are turning to poultry litter 
and other organic sources as an alternative to costly inorganic fertilizer sources.  The cost 
of inorganic fertilizers is ever increasing while U.S. fertilizer production is decreasing.  
Because natural gas is the primary raw material used to produce ammonia, the rise in 
U.S. gas prices has led to a 35% decline in U.S. ammonia production capacity and a 44% 
decrease in output between years 2000 and 2006.  National average fertilizer prices 
increased 113% between 2000 and 2007 due to increases in nitrogen costs.  During this 
seven year period, the price of ammonia, the main source of nitrogen in fertilizer 
production, increased 130% and the price of urea, the primary solid nitrogen fertilizer 
used in the U.S. rose 127% (Wen-yuan, 2007).  Due to the increases in inorganic 
fertilizer sources, the nutrients in poultry litter are more valuable than ever.   
 
10 
 
There is a great potential for the use of organic manure type products in the 
landscape and homeowner sector.  Increased awareness of environmental impacts from 
the use and manufacture of inorganic fertilizer sources has caused many homeowners to 
seek more environmentally friendly products.  Recent trends such as ?Going Green? have 
made the use of organic products more desirable.  In a report of Georgia nurseries and 
landscape firms, 73% of landscape managers polled said they currently do not use 
composted or manure products as a fertilizer.  The majority of the landscapers surveyed 
said however, that they do use some sort of manure based product for amending 
landscape beds used for annual and perennial bedding plants.  No nursery polled reported 
using any manure-based products.  About one-third of the nurseries and landscapers said 
they would use a manure type product if it were available and cost effective (Wolfe and 
Humphries, 2007).  Little research has been done in the areas of using poultry litter as a 
primary nutrient source for landscape and nursery operations, partially due to the limited 
availability of the products in some areas and also the limited awareness of the cost 
benefits of organic fertilizers. 
The majority of research with poultry litter use is concentrated on the effects of 
amending row cropping systems, perennial grass fields and pastureland with poultry 
litter.  Growers of corn, wheat, sorghum, soybeans, cotton, and turfgrass systems all 
utilize poultry litter as a cheap and effective source of fertilizer (Evers, 1998).  
Application in large fields is easier with current equipment. These large field operations 
are usually in closer vicinity to the poultry houses, which greatly decreases the farmers 
shipping costs, which is the most expensive and limiting factor in the widespread use of 
 
11 
 
poultry litter as a fertilizer.  There is an abundance of research in this area, particularly in 
regard to application of poultry litter to row crop lands.  Research has shown that poultry 
litter benefits soils by alleviating soil compaction problems.  Researchers reported that 
the application of organic amendments to compacted soils may minimize the negative 
impacts of soil compaction by increasing nitrogen mineralization and availability for 
crops in agricultural soil by promoting better conditions for soil microorganisms to thrive 
(Pengthamkerrati et al., 2005). 
In 1995 research began in south central Texas to evaluate poultry litter effects on 
coastal bermuda grass growth and development.  Tests focused on the amount of nutrient 
infiltration into the soil profile at various depths, evaluating nutrient leaching potential.  
In the first two years of the study, plots fertilized with commercial inorganic type 
fertilizers outperformed the plots fertilized with poultry litter.  In the following two years 
when no fertilizer was applied, plots amended with poultry litter outperformed the 
commercial fertilizer plots, indicating a slow release of nitrogen overtime from the 
poultry litter (Grichar et al., 2005).  In another study by Evers in 1998, results indicated 
that an application rate of 3.6 metric tons per 0.4 hectare (4 tons per acre) greatly 
improved bermuda grass production without causing buildup of unutilized nutrients such 
as phosphorus (which is usually a major concern).  A rate of 3.6 metric tons per 0.4 
hectare (4 tons per acre) was the nutrient equivalent of applying 6.8 kg N(15 lb), 6.8 kg P 
(15 lb) and 13.2 kg K(30 lb) of commercial fertilizer on the same area (Evers, 1998).  
Because of the N-P-K ratio found in most poultry litter, nitrogen becomes the limiting 
nutrient for grass production, which allows the buildup of other available nutrients.  
 
12 
 
Therefore after the initial application of poultry litter, supplemental nitrogen may need to 
be added via commercial fertilizers or from symbiotic fixation by legumes to utilize 
excess nutrients in the poultry litters (Evers, 1998). 
The most basic and obvious problem when reviewing research concerning poultry 
litter is that authors often fail to mention the nutritional content of the manure source 
being used, as it often varies widely from source to source.  Often unreported is whether 
the manure was cage layer, broiler litter or poultry litter, the type and amount of bedding 
material used, whether the product was raw, composted, liquid, etc. all of which have an 
enormous impact on the physical characteristics and nutritional value of the litter.  Raw 
manure may have a N-P-K nutritional value of 3-2-2 while after composting that same 
litter may have a N-P-K ratio of 1.5-3-1 (Mitchell and Tu, 2005).  This difference in 
nitrogen concentrations will have an enormous impact on crop performance in any 
cropping system and should always be reported.  There are also many inconsistencies in 
fertilizer application rates found in the literature.  Some researchers state that it is safe in 
assuming a 0.45 kg of nitrogen per 92.9 square meters (1 lb of nitrogen per 1,000 ft
2
), 
recommendations for inorganic fertilizer could also be used as a pound per square foot 
recommendation for poultry litter and other organic sources. However, different nutrient 
release times, and the fact that it is safer to apply higher rates of organic fertilizers than 
inorganic fertilizers, due to the decrease in plant damage potential, can dramatically 
impact proper poultry litter application rates.  These problems need to be addressed and 
discussed when researching poultry litter. 
 
13 
 
 Currently, research is aimed at the development of a sustainable poultry litter 
management practice to allow producers and farmers a set of guidelines for storing, 
composting, and applying poultry litter at a rate beneficial to the crop being grown while 
still protecting the areas water quality and eliminating odor and pathogen problems.  
Since 2004 researchers at Iowa State University have been conducting a six year study to 
determine the impact of poultry litter applications on nutrient uptake by crops and on 
surface and ground water quality.  Key results so far indicate that poultry litter applied at 
a rate of 68 kg per 0.4 hectares (150 lbs per acre) results in lower nitrate, phosphate, and 
bacteria concentrations in subsurface drainage water when compared to the equivalent 
application rates of commercial fertilizers (Kanwar, 2004).   
Another study indicates that application of aluminum sulfate or aluminum to litter 
has been found to decrease nutrient runoff, the main concern during long term storage 
and application (Moore et al., 1999). Also, application of zeolites, minerals with a micro-
porous structure, has been shown to reduce odor and gas emissions from poultry 
operations, increasing marketablity of the manure (McCrory and Hobbs, 2001). 
While there is an abundance of research dealing with poultry litter as a fertilizer 
for agronomic/row cropping systems, little research was found on using poultry litter 
commercially as a landscape fertilizer or as a nursery potting media amendment.  Broiler 
litter was evaluated as a soil amendment in landscape perennial and annual bedding 
plants (Reeder et al., 1992). Use of broiler litter incorporated into annual beds as a soil 
amendment resulted in plants equal to or larger than plants grown with traditional 
fertilizers (Reeder et al., 1992).  Researchers discovered that broiler litter application was 
 
14 
 
adequate to produce quality plants and while the nutrient levels of the manure may not 
completely replace traditional inorganic fertilizer sources, it can be an inexpensive 
alternative and reduce inorganic fertilizer requirements while providing an outlet for 
broiler litter disposal (Reeder et al., 1992).  Broiler litter compost ratios to peat and 
perlite were evaluated and a 1:3:4 ratio of broiler litter compost: peat: perlite produced 
the best annual and perennial plants from nursery grower?s standpoint (Allen et al., 
1994).  Consumer perceptions of composted broiler litter were also studied by Behe et al. 
(1991).  Consumers were polled on their thoughts and concerns with using composted 
broiler litter as a soilless potting mix and asked if they would be willing to use a product 
that contained mostly composted broiler litter.  They were later given three different 
potting mixes and rated the plants being grown in each mix on factors including water 
needed, foliar color, unpleasant odor, and overall plant health.  Participants in the study 
rated the potting mixes with composted broiler litter as high or higher than 2 
commercially available potting mixes based on perceived water holding capacity, plant 
foliar color, absence of unpleasant odor, and general plant health.  Results indicated that a 
potting mix comprised of predominately composted broiler litter does not appear to have 
an odor problem, but it was more of a perceived odor problem by the consumers (Behe et 
al., 1991).  Composted poultry litter has also been shown to improve growth in roses 
planted in the landscape (Warren and Safly, 1990). 
Altland (2002) evaluated fertilization practices for landscape bedding plants.  
Fertilizer treatments were applied to landscape bedding plants in raised beds simulating 
an urban landscape.  Fertilizers evaluated included: Osmocote 14-14-14 and 17-7-12 
 
15 
 
controlled release fertilizers (CRF?s), 13-13-13 and 15-0-15 granular water-soluble 
(GWS), and industry practice treatment (IP) of incorporating a CRF preplant and 
topdressing a GWS fertilizer postplant, and an organically-based fertilizer (OBF) 
composed of recycled newspaper and raw chicken manure.  Data collected included foliar 
color ratings, growth index, foliar nitrogen (% of dry weight), shoot dry weight, and 
inorganic N recovered in soil solution from suction-cup lysimeters.  Results indicate that 
CRF?s generally improved foliar color and plant size compared to GWS fertilizers, while 
reducing total-N recovered in soil-water.  OGFs containing poultry litter generally 
resulted in larger, more attractive (higher foliar color ratings) plants than those fertilized 
with any inorganic fertilizer tested.  While plants were larger and more attractive when 
fertilized with OGF, high salt levels from poultry litter caused wilting and/or mortality in 
some plants early in experiments and resulted in high levels of total-N recovered from 
soil-water.  One possible way to alleviate these problems is composting the litter prior to 
use in the landscape. 
Composted poultry litter has high potential in the container nursery industry, and 
in particular, as an amendment with high wood containing nursery container potting 
substrates or as a sphagnum peat moss replacement.  Turkey litter has shown to be a 
beneficial component in nursery production.  Tyler et al. (1993a, 1993b, 1993c) evaluated 
turkey poultry litter chemical, physical and thermal properties when used in combination 
with pinebark as a substrate and how it affected plant growth.  Results indicate that 
substrates were favorable when poultry litter was incorporated in low volumes.  Results 
by Fulcher et al (2002) also indicated that substrates containing composted poultry litter 
 
16 
 
at low volumes were generally beneficial to plant growth.  Poultry litter provides macro 
and micronutrients needed for plant growth, which makes it a viable option for use in 
container substrates.  While results are generally favorable, poultry litter has 
characteristically high soluble salt levels, which can damage sensitive crops (Allen et al., 
1994).  Testing is needed prior to amending any substrate with composted poultry litter to 
ensure a biologically stable compost, and fresh manure is never recommended due to 
high ammonia and salt levels, as well as the presence of pathogens and diseases (Midcap, 
1995). 
  Container substrate components have been the focus of much research since the 
large expansion in the industry in the 1950?s (Davidson et al., 2000).  Prior to the 1960?s, 
field soil and peat were the primary components used in container-plant production. 
However, undesirable physical properties and potential pathogen and disease problems 
associated with the use of field soil led researchers to evaluate pinebark as a potential 
new substrate component (Lunt and Kohl, 1956; Scott and Bearce, 1972).  Pinebark is 
removed from trees prior to lumber processing and in the past was stockpiled at lumber 
facilities.  Lumber facilities needed a means for bark disposal when pinebark began to 
accumulate. In the 1970?s researchers discovered that bark had ideal physical and 
chemical properties, was inexpensive, readily available, pathogen free, and was ideal for 
horticultural applications (Airhart et al., 1978; Brown and Pokorny, 1975; Cotter and 
Gomez, 1977; Natarella, 1976; Pokorny and Delaney, 1976).  Today nursery and 
greenhouse substrates in the U.S. are composed primarily of aged pinebark and Canadian 
 
17 
 
sphagnum peat moss.  Pinebark and peat moss are ideal because they are largely inert, 
pathogen free, and have been readily available in the past (Boyer, 2008).   
In recent years however there has been a consistent decline in availability of 
pinebark.  Due to reduced domestic forestry production, increased importation of logs 
(with no bark), increased in-field harvesting (leaving bark on the forest floor rather than 
at the mill), and the use of pinebark as a source of fuel, what was once a forestry waste 
product is now a valuable commodity (Lu et al., 2006).  This reduction in pinebark 
supplies along with increased shipping costs has made pinebark hard to find for some 
growers.  Costs associated with shipping peat from Canada or Europe could make peat a 
cost-prohibitive component of greenhouse substrates.  Shipping to the U.S. from Canada 
can cause peat moss to be more than half the cost of total growing material (Boyer, 
2008).   
Another problem associated with the use of peat moss is that peat is a slowly 
renewable resource.  Some peat bogs in Canada and Europe will be closed within the next 
decade due to over-harvesting (Carlile, 2004).  As a result of these major changes in the 
industry, researchers continue to seek new possible alternatives that could replace 
pinebark and peat as the main components for nursery and greenhouse production. 
Recent research has identified Clean Chip Residual (CCR) as a potential substrate 
substitute for pinebark and peatmoss (Boyer et al., 2008).  CCR is a by-product of 
forestry production process of thinning pine plantings using mobile in-field equipment 
when a plantation reaches 10-15 years in age.  In-field harvesting results in two products 
Clean Chips (used for making paper products) and CCR (everything else, including 
 
18 
 
wood, needles, and bark).  CCR is comprised of approximately 50% wood, 40% bark, 
and 10% needles and is either sold for boiler fuel or left in the field and spread across the 
harvesting area.  When sold as fuel, CCR is valued at $18-24/ton ($3 to $4/yd
3
).  When 
compared to the cost of pinebark ($12 to 20/yd
3
) and the cost of peat (around $70/yd
3
), 
CCR has the potential to provide significant savings to producers (Boyer, 2008).  Studies 
by Boyer et al. (2008) indicate plants grown in CCR grew as well or better than plants 
grown in standard pinebark peatmoss combinations.   
Another potential substrate material is WholeTree.  WholeTree (WT) is composed 
of the entire shoot portion of the tree and contains around 80% wood fiber depending on 
the age of the tree harvested.  WholeTree can be obtained from low-value biomass that is 
acquired during pine plantation thinning, much like CCR, or in some instances, when a 
pine plantation is clear cut in order to replant (Boyer, 2008).  Studies by Fain and Gilliam 
(2006) indicate that annual vinca (Catharanthus roseus) grown in WT had similar growth 
to plants grown in PB.  Fain et al. (2008) reported WT composed of three species of pine 
could each be successfully used as a growth substrate for annual vinca.  Fain et al. (2006) 
evaluated WT in the production of herbaceous greenhouse crops (marigold, Tagetes 
patula ?Little Hero Yellow?; lantana, Lantana camara ?Lucky Red Hot Improved?; and 
petunia Petunia x hybrida ?Dreams Pink?).  Plants were grown in 100% WT and ground 
with a hammermill to three different screen sizes and mixed on a v:v basis with peat moss 
and compared to nursery standard peat moss blends.  In general, plants grown in WT 
substrates were smaller than plants grown in standard blends, but plants increased in size 
with increasing peat moss percentage. 
 
19 
 
Wright and Browder (2005) demonstrated that with proper nutrition and 
irrigation, ground pine logs are comparable to pinebark as a container substrate.  In this 
study root growth of Japanese holly (Ilex crenata ?Chesapeake?), azalea (Rhododendron 
obtusum ?Karen?) and marigold (Tagetes erecta ?Indica Gold?) was more extensive in 
ground pine wood chips than in aged pinebark.  Results also show that these high wood 
substrates exhibited acceptable pH ranges, had no toxic nutrient levels, and no excessive 
shrinkage was observed.   
One major concern associated with the use of a wood based substrate is the initial 
immobilization of nitrogen.  Reports indicate that substrates containing high wood 
content often require higher fertilizer applications to achieve similar plant growth as 
standard substrates (Wright et al., 2008).  Use of composted poultry litter in high wood 
based substrates could potentially balance the initial nitrogen immobilization.  
Composted poultry litter also has potential to provide growers with a peat moss 
alternative.  Poultry litter co-composted with sawdust was shown to grow the largest 
marigold (Tagetes patula 'Bonanza Yellow') and provide a favorable alternative to 
peatmoss (Freeman and Cawthon, 1999).  Results from this study also indicated that 
composted poultry litter has similar physical properties to peat moss.  Boyer et al. (2006) 
tested substrates composed up 50% to 100% whole pine trees (Pinus taeda) for the 
production of container grown lantana (Lantana camara) in combinations with peat and 
poultry litter compared to a pinebark:sand substrate.  Results indicate that the poultry 
litter treatments with high wood content were statistically similar to the wood: peat and 
pinebark: sand combinations.  
 
20 
 
Based upon current and past research, poultry litter could become a valuable 
commodity in the horticulture industry.  Poultry litter has benefits when used in the 
landscape and in soilless container substrates, but it also has limitations.  Transportation 
costs are the main problem is mass marketing poultry manure nationally because moving 
manure long distances results in high transportation costs, and the cost-saving advantages 
of using poultry litter become mute (Grichar et al., 2005).  In areas of intense poultry 
production, such as the southeastern U.S., litter could be attained at a low cost in most 
situations. Transportation costs would be negligible considering the close proximity of 
poultry operations in these areas.   An additional problem is the variability in nutrient 
content from source to source and the temporary odor and pathogen problems during 
storage or after application make it a less desirable nutrient source for some homeowners.  
Composting eliminates most odor and pathogen problems, and generally provides a 
nutritionally stable product.  Even after composting, nutritional analysis is needed before 
use in the landscape or in a container substrate.  Most authors conclude that while poultry 
litter will never replace commercial fertilizers as a whole, it can be a cost effective source 
of fertilizer for plants while providing an outlet for poultry farmers to dispose of poultry 
waste.  The problem with current disposal methods such as mass application to farm and 
pasturelands, is the potential for negative environmental effects that large quantities of 
manure have on local ground and surface water supplies.  When managed properly, 
poultry litter is the most valuable of all animal manures, having the highest 
concentrations of essential nutrients needed for plant growth. 
 
21 
 
Due to the excess of poultry litter production and the inevitable expansion of the 
poultry industry, research is needed to develop environmentally sound disposal methods, 
while still providing crops an efficient and economical nutrient source.  Based upon past 
and current research, the production of nursery and greenhouse crops in alternative 
substrates and amendments such as composted poultry litter could be a viable option.  
Research also indicates that composted poultry litter can be used effectively in the 
landscape and provide landscapers and homeowners with an inexpensive, 
environmentally friendly supplement or alternative to costly inorganic fertilizers.  Slight 
changes in production practices are needed, but these changes should be minimal.  
Composted poultry litter has the potential to provide a positive economic benefit to the 
horticulture industry by providing a fertilizer source, landscape amendment, and 
container substrate alternative that is locally produced, sustainable, and environmentally 
sound. 
Research is needed to determine what areas of the horticulture industry that 
composted poultry litter can be most beneficial.  The objective of this research was to 
determine how composted poultry litter can be used beneficially in the landscape and 
container nursery industries while providing poultry producers an environmentally sound 
means of waste disposal.  Results from these studies indicate that composted poultry litter 
may have potential as a valuable alternative to inorganic fertilizers and provide a suitable 
substrate supplement in containerized ornamental crop production. 
 
  
 
22 
 
       
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29 
 
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30 
 
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31 
 
 
?
 
 
 
 
 
CHAPTER II 
 
Evaluation of Composted Poultry Litter as a Substrate Amendment for Whole Tree, 
Clean Chip Residual, and Pinebark for Container Grown Woody Nursery Crops 
 
Abstract 
 Whole Tree (WT) and Clean Chip Residual (CCR) are potential new nursery 
substrates that are by-products of the forestry industry containing high wood content.  
Initial immobilization of nitrogen is one limitation of these new substrates; however the 
addition of composted poultry litter (CPL) to substrates containing high wood content 
could balance initial nitrogen immobilization and provide an inexpensive fertilizer source 
for growers.  This study evaluated five woody nursery crops being grown in WT, CCR, 
and pinebark (PB) with the addition of CPL or peat as a substrate amendment.   Results 
indicate that woody nursery crops can be grown successfully in WT and CCR substrates 
6:1 (v:v) with CPL.  Use of CPL in WT and CCR substrates may provide an alternative to 
traditional PB plus peat based combinations in container plant production while 
providing poultry producers an environmentally sound means of waste disposal. 
 
Introduction 
 Pinebark (PB) and PB plus peat combinations are the predominant substrate 
components for container plant production in the southeastern United States (Boyer et al., 
2008). Reduced forestry production in the United States paired with the increased use of 
 
32 
 
 
?
PB as a fuel source is reducing the availability of PB (Lu et al, 2006).  The growing 
concern over future availability of PB, high shipping costs associated with peat and the 
argument that peat is a relatively non-renewable resource, has led to the exploration for 
alternatives to these two commonly used substrate components (Boyer et al., 2008; Fain 
et al., 2008).    
Whole Tree (WT) consists of entire pine trees (Pinus taeda L.) which are 
harvested from pine plantations at the thinning stage, chipped whole and later 
hammermilled through specific screen sizes based upon crop specification (Fain et al., 
2008).  Whole Tree (90% wood fiber) is made up of wood, bark, limbs, needles, cones, 
and is used fresh after grinding.  Studies suggest WT can be used successfully in 
production of greenhouse crops (Fain et al., 2007; Fain et al., 2008). 
 Mobile field equipment is now being used for in-field pine tree harvesting 
operations which process trees into ?clean chips? for pulp mills, leaving behind a residual 
material composed of about 50% wood, 40% bark, and 10% needles (Boyer et al., 2008).  
This material, referred to as ?clean chip residual? (CCR) is either sold as boiler fuel or 
spread across the harvesting area.  CCR accounts for about 25% of the total biomass 
harvested.  With millions of acres in the southeast in forestry production, CCR has the 
potential to provide an economical and sustainable substrate alternative for the nursery 
industry (Boyer et al., 2008). 
 The major concern associated with the use of a wood based substrate is the initial 
immobilization of nitrogen.  Reports indicate that substrates containing high wood 
content require higher fertilizer applications to achieve similar plant growth as standard 
 
33 
 
 
?
bark or peat based substrates (Gruda et al., 2000; Jackson et al., 2006; Wright et al., 
2008).  Use of CPL in wood based substrates could balance the initial nitrogen 
 immobilization while providing poultry farmers a new outlet for the growing problem of 
waste disposal. 
 One of the problems in modern agricultural operations is the large amount of 
waste generated by intense animal production in concentrated areas.  Historically, land 
application was the preferred method of poultry waste disposal with almost 90% of all 
poultry litter being applied to agricultural land (Daniel et al., 1995).  EPA regulations 
now require larger poultry operations (> 100,000 birds) or operations within close 
proximity to lakes, streams, rivers, ground-water supplies, etc., to obtain permits and 
dispose of manure according to a nutrient management plan (NMP) (EPA, 2008).  For 
example, the average livestock operation in the Mid-Atlantic states would have to 
increase the amount of land used for spreading animal manures from 28 to 161 hectares 
(69 to 398 acres) in order to meet a nitrogen-based application standard (McBride and 
Key, 2003).  In areas where poultry production is intense and concentrated, such as in the 
southeastern United States, excess manure still exists and limits placed on the amount of 
litter that can be land applied on an annual basis leaves poultry producers in need of new 
economical ways to safely dispose of this waste.  Typical poultry litter will have the 
following nutrient ranges: Nitrogen from 2.1 to 6%, Phosphorus from 1.4 to 9%, 
Potassium from 0.8 to 6.2%, Calcium from 0.8 to 6.1%, Magnesium from 0.2 to 2.1%, 
and Sulfur from 0.1 to 0.8%, on a dry-weight basis (Mitchell et al., 1995).  Nutrients 
present in poultry manure can provide an economical alternative to costly inorganic 
fertilizers and soil amendments.  Fuel costs associated with importing peat from Canada 
 
34 
 
 
?
are decreasing grower?s profit margins (Fain et al., 2007).  As fuel costs increase 
fertilizer becomes more expensive.   Fertilizer prices rise with the cost of natural gas 
which is the primary raw material used to produce ammonium nitrate (Wen-yuan, 2007). 
National composite fertilizer prices increased 113% between 2000 and 2007 due to 
increases in nitrogen costs.  During this seven-year period the price of ammonium nitrate, 
the main source of nitrogen in fertilizer production, increased 130% and the price of urea, 
the primary solid nitrogen fertilizer used in the US, rose 127% (Wen-yuan, 2007).   The 
USDA Economic Research Service reported a 20% rise in national fertilizer prices in 
2007 and an 18% increase at the end of 2008. As fertilizer prices continue to rise, it is 
important to search for cost saving alternatives to conventional fertilizers. Poultry litter 
has higher concentrations of nutrients than other animal wastes, is relatively dry (easily 
mixed with substrates), and is totally collectable (Stephenson et al., 1990).   Adding CPL 
to PB, WT, or CCR substrate could provide the nursery industry with a valuable substrate 
component and a low cost nutrient supplement while providing poultry producers with an 
environmentally friendly means of waste disposal.  Research has shown that composted 
organic material has the potential to improve the physical and chemical properties of 
container substrates (Hemphill et al., 1984; Tyler et al 1993a).  In studies by Bilderback 
and Fonteno (1991), growth of Cotoneaster dammeri were improved when grown in a 
substrate composed of PB, rockwool, and CPL when compared to plants grown in 
substrates containing only PB.  In a study by Tyler et al. (1993b) Cotoneaster dammeri 
C.K. Schneid. ?Skogholm? and Hermerocallis sp. ?Red Magic? grew as well in substrates 
amended with composted turkey litter as plants grown in a 100% pinebark substrate.   
 
35 
 
 
?
 The objective of this study was to evaluate WT, CCR and PB with the addition of 
CPL as a substrate for production of container-grown nursery crops.    
 
Materials and Methods 
Experiment 1 
 Experiment 1 was conducted at the Auburn University Ornamental Horticulture 
Research Center, located in Mobile, Al.  Five species (Rhododendron x ?Iveryana? 
(azalea), Buxus sempervirens L. (boxwood), Ilex crenata Thunb. ?Compacta? (holly), 
Loropetalum chinense Oliv. ?Chang?s Ruby? (loropetalum), and Ternstroemia 
gymnanthera Thunb. (ternstroemia)) were transplanted from cell pack liners (72, 48, 38, 
50, and 50 cell pack liners, respectively) into #1 containers on 31 May 2007, placed in 
full sun and over-head irrigated as needed. Treatments consisted of nine substrates 
composed of varying ratios of PB, WT, CCR, and CPL (Table 1).  Treatments included  
WT and CPL (6:1 v:v) (WT:CPL), CCR and CPL (6:1 v:v) (CCR:CPL), PB:CPL (6:1 
v:v) (PB:CPL), 100% WT, 100% CCR, 100% PB, WT:Peat (6:1 v:v) (WT:Peat), 
CCR:Peat (6:1 v:v) (CCR:Peat), and PB:Peat (6:1 v:v) (PB:Peat).   Whole Tree and CCR 
used in this study were processed to pass a 0.64 cm (0.25 in) and 0.95 cm (0.375 in) 
screen, respectively using a swinging hammer mill (No. 30 C.S. Bell, Tifton, OH).  Fresh 
poultry litter used was obtained from Greenville, AL and was composted in an in-vessel 
rotating drum digester (BW Organics, Inc. Sulphur Springs, TX) for two weeks until 
temperature fluctuations indicated that the material was fully composted.  Nutrient 
content of CPL based on analysis by Brookeside Laboratories Inc. (New Knoxville, OH) 
was 2.5% nitrogen, 1.4% phosphorous, and 2.3% potassium on a wet weight (as is) basis. 
 
36 
 
 
?
Each substrate treatment was pre-plant incorporated with Harrell?s (Harrell?s Fertilizer 
Inc., Sylacauga, AL) 18N-2.6P-9.9K (15-6-12) (8 to 9 month formulation) at 10.7 kg/m
3
 
(18 lb/yd
3
), 1.2 kg/m
2
 (2 lb/yd
3
) gypsum and 0.9 kg/m
2
 (1.5 lb/yd
3
) Micromax (The 
Scotts Co., Maryville, OH).  Plants were arranged by species in a randomized complete 
block design with eight single plant replications. 
 Pour-through extractions were conducted at 7, 15, 30, 60, 90, 120 and 180 days 
after transplanting (DAT) and analyzed for pH and electrical conductivity (EC) using the 
Virginia Tech pour-through technique (Wright, 1986).  Subjective foliar color ratings 
were taken at 60 and 120 DAT on a scale of 1 to 5 where 1 = severe chlorosis, 2 = 
moderate chlorosis, 3 = slight chlorosis, 4 = light green, and 5 = dark green.  Growth 
indices [(height + width1 + width2)/3] were taken at 120 and 340 DAT, and shrinkage 
measurements (measured in cm from the media surface to the top of the pot) were taken 
on boxwood at 120 DAT and 340 DAT.  Root ratings were taken by rating root coverage 
of the outer surface of the root ball at 340 DAT on a scale of 1 to 5 with 1 = no visible 
roots, 2 = 25% of surface covered with roots, 3 = 50% root coverage, 4 = 75% coverage, 
and 5 = 100% coverage.   
 Recently matured, current season terminal shoots (5.1 to 7.6 cm (2-3 in)) (11) 
were sampled from ternstroemia at 340 DAT.  Foliar samples (four replications per 
treatment) were analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), 
magnesium (Mg), sulfur (S), boron (B), iron (Fe), manganese (Mn), sodium (Na), Copper 
(Cu), and zinc (Zn).  Foliar N was determined by combustion analysis using a 1500 N 
analyzer (Carlo Erba, Milan, Italy).  Remaining nutrients were determined by microwave 
digestion with inductively coupled plasma-emission spectrometry (Thermo Jarrel Ash, 
 
37 
 
 
?
Offenbach, Germany).  Data were analyzed using Duncan?s Multiple Range test (P < 
0.05) using a statistical software package (SAS Institute version 9.1, Cary, NC). 
 
Experiment 2 
 Experiment 2 was conducted at the Auburn University Ornamental Horticulture 
Research Center, in Mobile, Al.  Materials and methods for experiment 2 were similar to 
experiment 1 with the following exceptions.   Five species (Rhododendron x ?Amelia 
rose? (azalea),  Buxus sempervirens L. (boxwood),  Ilex crenata Thunb. ?Compacta? 
(holly),  Loropetalum chinense Oliv. ?Chang?s Ruby? (loropetalum), and Ternstroemia 
gymnanthera?Bronze Beauty? Thunb. (ternstroemia)) were transplanted from cell pack 
liners (72, 48, 38, 50, and 50 cell pack liners, respectively) into #1 containers on 17 April 
2008, placed in full sun and over-head irrigated as needed.  Substrate treatments were 
similar to experiment 1.  Fresh poultry litter used was obtained from Greenville, AL and 
was composted in an in-vessel rotating drum digester (BW Organics, Inc. Sulphur 
Springs, TX) for two weeks until temperature fluctuations indicated that the material was 
fully composted.  CPL was analyzed by Brookside Laboratories Inc. (New Knoxville, 
OH) and analysis showed 2.3% nitrogen, 1.5% phosphorous, and 2.3% potassium on a 
wet weight (as is) basis.  
 Substrate air space (AS), container capacity (CC), and total porosity (TP) were 
determined following procedures described by Bilderback et al. (1982). Substrate bulk 
density (BD) (measured in grams per cubic centimeter) was determined from 374.5 cm
3
 
samples dried in a 105? C forced air oven for 48 h.  Substrates were analyzed for particle 
size distribution (PSD) by passing a 100-g air-dried sample through 12.5, 9.5, 6.35, 3.35, 
 
38 
 
 
?
2.36, 2.0, 1.4, 1.0, 0.5, 0.25, and 0.11 mm sieves with particles passing the 0.11mm sieve 
collected in a pan.  Sieves were shaken for 3 min with a Ro-Tap (Ro-Tap RX-29, W.S. 
Tyler, Mentor, OH) sieve shaker (278 oscillations/min, 159 taps/min). 
 Pour-through extractions were conducted at 7, 30, 60, 90, 120, 285, and 390 days 
after transplanting (DAT) and analyzed for pH and electrical conductivity (EC) using the 
pour through technique (Wright, 1986).  Subjective foliar color ratings were taken at 60 
and 120, and 390 DAT on a scale of 1 to 5 where 1 = severe chlorosis, 2 = moderate 
chlorosis, 3 = slight chlorosis, 4 = light green, and 5 = dark green.  Growth indices 
[(height + width1 + width2)/3] were taken at 60 and 390 DAT, and shrinkage 
measurements (measured in cm from the media surface to the top of the pot) were taken 
on boxwood at 7, 30, 60, and 390 DAT.  Root ratings were taken by rating root coverage 
of the outer surface of the root ball at 390 DAT on a scale of 0 to 10, 0 = 0% of surface 
covered with roots, 10 = 100% of the rootball surface covered with roots.  Data were 
analyzed using Duncan?s Multiple Range Test (P < 0.05) using a statistical software 
package (SAS Institute version 9.1, Cary, NC). 
 
Results 
Experiment 1 
pH and EC.  Addition of CPL tended to increase pH while peat caused a decline in pH 
(Table 1.1).  Initial data at 7 DAT showed that pH levels for PB (3.8), CCR (4.7), and 
WT (5.2) were increased to pH levels of 5.8, 6.7, and 6.9 respectively when CPL was 
added to the respective substrates.  Conversely, addition of peat tended to lower pH for 
PB (3.8 to 3.7), CCR (4.7 to 4.2) and WT (5.2 to 4.3).  pH levels for all substrates 
 
39 
 
 
?
amended with CPL declined over time; however pH levels at the end of the study were 
within the desired range (4.5 to 6.5) (Yeager et al., 2007).  However, substrates with peat 
added or 100% WT, CCR, or PB had unacceptable pH levels at 180 DAT (less than 4.5).   
 Electrical conductivity (EC) levels were initially high (7 DAT) in WT, CCR, and 
PB substrates amended with CPL (1.3, 1.2, and 1.6 dS/m respectively) (Table 1.1).  
However by 30 DAT all CPL treatments were within the recommended range (0.5 to 1.0 
dS/m) with the exception of PB:CPL which remained slightly higher (Yeager et al., 
2007).   At 60 DAT all CPL treatments had acceptable EC levels and remained within an 
acceptable range for the duration of the study.  Substrates amended with peat had slightly 
higher EC levels than 100% substrates (WT, CCR, and PB) which had acceptable EC 
levels throughout the study.  In general, CPL treatments had the highest pH and the 
highest EC throughout the study.  pH levels of substrates amended with CPL were more 
favorable for plant growth than 100% WT, CCR, and PB or substrates containing peat 
which remained very acidic throughout the study.  While high EC levels may be a 
concern for more sensitive crops, the majority of woody nursery crops would not be 
affected by the EC levels exhibited in CPL treatments which peaked at 1.6 dS/m and 
declined quickly. 
 
Growth Indices (GI).  Growth indices data [(height + width1 + width2)/3] at 120 DAT 
indicated that hollies were larger when grown in CCR:CPL, PB:CPL, 100% WT, 100% 
CCR, or CCR:Peat (Table 1.2).  At 340 DAT hollies grown in 100% WT, CCR, or PB as 
well as CCR:Peat grew the largest; however growth was statistically similar to all other 
treatments except WT:CPL and PB:Peat which were smaller (Table 1.2).  At 120 DAT 
 
40 
 
 
?
boxwood gown in CCR:CPL were larger than plants in all other substrates, a trend that 
continued at 340 DAT.  The least growth in boxwood occurred in substrates containing 
100% PB or PB:Peat which may be attributed to low pH levels.  Loropetalum were larger 
in substrates containing 100% CCR or CCR:Peat at 120 and 340 DAT while the least 
growth occurred in WT:CPL.  Azaleas grown in substrates containing 100% CCR were 
the largest at 120 DAT; however, by 340 DAT growth indices of plants grown in 100% 
CCR were statistically similar to WT:Peat and CCR:Peat.  No differences were observed 
in the growth of ternstroemia in any substrate throughout the study.   
 
Foliar Color Ratings (FCR).  Foliar color ratings (FCR) were similar among all 
treatments in holly at 60 and 120 DAT (Table 1.3).  At 60 DAT, boxwood grown in 
WT:CPL, CCR:CPL, PB:CPL, 100% WT, 100% CCR, WT:Peat, and CCR:Peat had 
slightly higher FCR than other treatments, however at 120 DAT, no significant 
differences existed.  Loropetalum FCR were highest in 100% CCR at 60 DAT; however 
by 120 DAT, 100% WT received the highest ratings.  Azaleas grown in WT:Peat 
received the highest FCR at both 60 and 120 DAT.  Azaleas had the lowest FCR in 
treatments containing CPL, possibly due to higher pH levels.  Ternstroemia FCR was 
similar for plants grown in 100% WT, CCR, PB, PB:Peat, and CCR:Peat and this trend 
continued at 120 DAT. 
 
Root Ratings.  Hollies grown in substrates containing CPL had the lowest root ratings and 
root ratings were statistically similar among all other treatments (Table 1.4).  Boxwood 
root ratings were highest in CCR:CPL and the lowest root rating occurred in substrates 
 
41 
 
 
?
containing PB:Peat.  Root ratings in loropetalum, azalea, and ternstroemia were all lowest 
in WT:CPL; however, all other treatments had root ratings similar to the traditional 
PB:Peat substrate.   
 
Shrinkage.  Shrinkage measurements were all similar with the exception of WT:CPL and 
CCR:CPL which had more shrinkage than any other treatment at 340 DAT (Table 1.4) 
possibly due to further decomposition of the WT and CCR.  Interestingly, PB:CPL 
substrates had the least shrinkage of any treatment, even less than PB:Peat combination 
(3.6 to 4.3).  High wood substrates (WT and CCR) had more shrinkage in general than 
treatments containing PB.  However, similarities between 100% WT, CCR, and PB 
indicate that the use of high wood substrates alone does not increase media settling due to 
wood decomposition. 
 
Tissue Nutrient Content.  Tissue nutrient content of ternstroemia was similar among 
treatments for K, Fe, Cu, and Zn (Table 1.5).  In general, all treatments contained nutrient 
contents higher than or equal to the sufficiency range for each nutrient level tested.  
Foliar N tended to be highest in 100% WT, 100% CCR, and 100% PB, as well as in 
WT:Peat and CCR:Peat.  Treatments containing CPL also tended to have the lowest foliar 
N.  Foliar P levels were highest in PB:CPL and CCR:Peat, however CCR:Peat P levels 
were similar to other treatments.   
 
42 
 
 
?
 
Experiment 2 
Physical Properties.  All substrates had acceptable air space (AS) except substrates 
containing PB, which had a higher than recommended AS (10-30%) (Table 2.1).  AS 
tended to increase with increasing particle size.  Container Capacity (CC) of all substrates 
were in the acceptable ranges (45-65%) (Yeager et al., 2007) except for PB:CPL and 
100% PB which were slightly lower. Total porosity results were within acceptable ranges 
for all substrates tested.  Bulk density (BD) results indicated that all substrates had 
acceptable BD with the exception of CCR:Peat, which was slightly lower than the 
recommended range (0.19 to 0.70 g/cm
3
) (Yeager et al., 2007). 
 
Particle Size Analysis.  Substrates containing PB had a higher component of large 
particles and fewer medium and fine particles than any of the other substrates (Table 2.2). 
100% CCR had the largest percentage of medium particles. WT:Peat had a higher 
percentage of fine particles than other substrates, but were similar to 100% WT and CCR.  
In general, 100% WT and CCR substrates had predominately medium sized particles. 
 
pH  and EC.  Similar to experiment 1, addition of CPL tended to increase pH while the 
addition of peat to substrates tended to decrease pH (Table 2.3).  At 7 DAT the addition 
of CPL increased pH levels of WT (5.5 to 7.4), CCR (4.8 to 7.4) and PB (4.2 to 6.9). 
Conversely, peat decreased pH in WT, CCR, and PB substrates to levels of 4.6, 4.1, and 
4.0, respectively.  pH levels generally tended to decrease in all substrates over time, and 
by 60 DAT, most substrates were within the desired range for container-grown nursery 
 
43 
 
 
?
crops (4.5 to 6.5) (Yeager et al., 2007).  Substrates were within acceptable ranges until 
285 DAT when all substrates without CPL dropped below desired levels, a trend that 
continued at 390 DAT. 
As in experiment 1, at 7 DAT EC levels were initially high in substrates 
containing CPL (Table 2.3).  However, by 30 DAT, all EC levels were within desired 
ranges (0.5 to 1.0) (Yeager et al., 2007) with the exception of PB:CPL which remained 
slightly higher.  After 60 DAT, EC began to gradually decline in all substrates, possibly 
due to depletion of fertilizer.  While all EC levels declined over time, substrates 
containing CPL generally had the highest EC levels all of substrates until 285 DAT when 
almost all substrate EC levels leveled off. 
 
Growth indices (GI).    At 60 DAT, GI indicated that hollies grown in PB:CPL were 
larger than hollies grown in all other treatments, while hollies grown in WT:CPL had the 
lowest GI (Table 2.4).  By 390 DAT, hollies grown in PB:CPL substrate continued to be 
larger than hollies grown in all other substrates.  GI of boxwood at 60 DAT were 
generally similar among all substrates.  By 390 DAT, boxwood grown in WT:CPL and 
CCR:CPL had a higher GI than boxwood grown in all other substrates, possibly due to 
the higher pH levels of these substrates.  Loropetalum showed little difference in growth 
at 60 DAT, however WT:CPL, 100% WT, 100% PB and all substrates containing peat 
tended to have higher GI.  By 390 DAT, substrates containing CPL along with 100% PB 
and PB:Peat substrate had higher GI than most other substrates.  Azalea GIs at 60 DAT 
indicated that 100% WT, 100% PB, and all substrates containing peat were largest, 
possibly due to the lower pH of these substrates.  By 390 DAT, 100% PB, 100% WT, and 
 
44 
 
 
?
all substrates containing peat grew larger azaleas than any other treatment, while azaleas 
grown in substrates containing CPL had the lowest GI.  Few statistical differences were 
observed in ternstroemia at 60 DAT, however at 390 DAT ternstroemia were largest in 
100% WT and all substrates containing peat.  Ternstroemia in substrates containing CPL 
tended to have the lowest GI, with the exception of PB:CPL which was similar to the 
PB:Peat nursery standard. 
 
Foliar Color Ratings (FCR).  No differences were observed in FCR of holly at 60 or 120 
DAT (Table 2.5).  Only slight differences occurred at 390 DAT, with WT:CPL, WT:Peat, 
and PB:Peat having slightly lower FCR than other treatments, however all substrates 
generally performed similarly. Small differences were observed in boxwood FCR at 60 
DAT, however by 120 DAT, there were no differences in FCR among boxwoods in any 
substrate.  By 390 DAT, again few differences were observed.  Generally boxwoods 
grown in substrates containing CPL tended to have a higher FCR than boxwoods grown 
in other substrates, however these differences were minimal.  At 60 and 120 DAT 
loropetalum tended to have higher FCR in substrates containing peat, however by 390 
DAT there were no differences in FCR among any substrate.  Azaleas had the highest 
FCR in 100% PB and WT:Peat substrates at 60 DAT, but were similar to other 
treatments.  At 120 DAT, azaleas tended to have the highest FCR when grown in 
substrates containing peat, but again at 390 DAT there were no differences in FCR 
among azaleas in any substrate.  Ternstroemia had the lowest FCR when grown in CPL at 
60 DAT, a trend that continued at 120 DAT.  By 390 DAT, 100% WT and 100% CCR 
 
45 
 
 
?
had the highest FCR, but FCR was similar to other treatments.  Little difference was 
observed in ternstroemia grown in any substrate. 
 
Root Ratings (RR).  Holly had the highest RR in 100% WT, however RR were similar in 
PB:CPL, 100% CCR, 100% PB, WT:Peat, CCR:Peat, and PB:Peat (Table 2.6).  Holly 
had significantly less roots in WT:CPL than in any other treatment.  In contrast, boxwood 
RR were highest in WT:CPL, and had similar root growth in CCR:CPL.  Loropetalum 
grown in 100% PB had highest RR, however PB:CPL, 100% CCR, and PB:Peat were 
similar.  As in experiment 1, azaleas had lowest RR in WT:CPL.  While ternstroemia in 
experiment 1 had significantly higher RR in WT:CPL, in experiment 2 WT:CPL along 
with CCR:CPL had the significantly lower RR than all other treatments.    
 
Shrinkage.  At 7 DAT substrate shrinkage was greatest in treatments containing WT, 
specifically WT:CPL, 100% WT, and WT:P.  PB:CPL and CCR:Peat had less shrinkage 
than any other treatment (Table 2.7).  This trend continued at 30 DAT.  By 60 DAT, 
WT:CPL and CCR:CPL treatments had significantly more shrinkage than any other 
treatment, possibly due to further decomposition of WT and CCR.  At the conclusion of 
the study WT:CPL had more shrinkage than any other treatment (6.4).  PB:Peat had less 
shrinkage than any other treatment, however shrinkage was similar to PB:CPL, 100% PB, 
and CCR:Peat. 
 
 
 
 
 
 
 
46 
 
 
?
Discussion 
 
 In summary, similarities among substrates in these studies amended with peat or 
CPL indicate that CPL could be an economically viable and sustainable substrate 
amendment for container plant production.  In both experiments, CPL tended to raise pH 
and peat tended to lower pH, particularly in the first 2 months.  At the conclusion of each 
experiment, treatments containing CPL were closer to the BMP suggested pH levels than 
any other treatments.   
 CPL increased EC levels in both studies, more dramatically in experiment 2 than 
in experiment 1.  However, in each study, EC levels quickly declined and were within 
recommended levels by 30 DAT. 
  While growth differences did occur with individual species throughout these 
studies, at the end of both studies all five species grown in high wood substrates (100%) 
had growth similar to plants grown in the PB:Peat commercial standard substrate.   FCR 
were also similar among treatments for most species throughout these studies.  RR results 
were again species specific concerning the use of CPL.  Similarly, in a study by Tyler et 
al. (1993b) results indicated that high EC levels resulting from incorporation of 
composted turkey litter may inhibit root growth of cotoneaster (Cotoneaster dammeri 
?Skogholm?) and daylily (Hemerocallis sp. ?Red Magic?).  However, in both studies all 
species grown in alternative wood based substrates had root coverage comparative to the 
grower standard PB:P.  WT:CPL had the most shrinkage in both studies, possibly due to 
further decomposition from the WT.  The smaller particle size of the WT used in 
comparison with CCR and PB also contributed to the high shrinkage of this substrate, 
especially when CPL was added to WT.  It is important to note, that when WT was used 
 
47 
 
 
?
at 100%, or in combination with peat, shrinkage was similar to 100% PB and PB:Peat in 
experiment 1.  
 Use of CPL in container production could possibly balance initial nitrogen 
immobilization which is often a concern when using substrates with high wood content.  
CPL could also be used as a peat substitute while growing non-sensitive crops. As PB 
supplies decline and fertilizer prices continue to increase, growers must look to the future 
for economically sustainable substrates.  These results show high wood substrates with or 
without CPL (depending on crop) have potential to address future industry needs. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
48 
 
 
?
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Bilderback, T.E., and W.C. Fonteno. 1991. Use of horticultural rockwool, poultry litter 
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Fain, G.B., C.H. Gilliam, J.L. Sibley, and C.R. Boyer.  2007.  Production of hardy mums 
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 HortTechnology 18:111-115. 
 
Yeager, T., T. Bilderback, D. Fare, C. Gilliam, J. Lea-Cox, A Niemiera, J. Ruter, K. Tilt, 
 S. Warren, T. Whitwell, and R. Wright.  2007.  Best management practices: Guide 
 for producing nursery crops. 2
nd
 ed. Southern Nursery Assn.  Atlanta, Ga. 
 
 
 
 
 
 
 
 
 
 
  
Treatment EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m)
6:1 WT
X
:CPL
W
0.3 e 6.3 a 0.4 b 5.9 a 0.3 a 5.3 b 0.24 a
6:1 CCR
V
:CPL 0.5 cde 5.9 a 0.8 a 6.0 a 0.2 a 5.8 a 0.15 bc
6:1 PB
U
:CPL 1.2 a 5.5 b 0.5 ab 5.2 ab 0.2 a 4.9 b 0.13 c
100% WT 0.4 de 5.1 c 0.4 b 3.8 c 0.3 a 3.4 c 0.2 ab
100% CCR 0.8 b 4.6 ed 0.6 ab 4.5 bc 0.3 a 3.4 c 0.18 abc
100% PB 0.7 bc 4.3 e 0.5 ab 3.5 c 0.2 a 3.3 c 0.21 ab
6:1 WT:Peat 0.4 de 4.7 d 0.4 b 4.6 bc 0.2 a 3.5 c 0.2 abc
6:1 CCR:Peat 0.6 bcd 4.4 ed 0.5 b 3.7 c 0.2 a 3.7 c 0.18 abc
6:1 PB:Peat 0.8 b 4.3 e 0.4 b 3.8 c 0.3 a 3.5 c 0.19 abc
U
PB = Pinebark.
Table 1.1  Experiment 1. Solution pH and electrical conductivity (EC) of substrates
Z
.
          7 DAT
Y
30 DAT            60 DAT           120 DAT          180 DAT
pH EC (dS/m) pH
6.7 b 1.2 a 6.4 b
6.9 a
T
1.3 a 6.6 a
5.2 d 0.4 b 4.9 d
5.8 c 1.6 a 5.6 c
3.8 g 0.4 b 3.8 g
4.7 e 0.4 b 4.6 e
4.2 f 0.6 b 4.3 f
4.3 f 0.6 b 4.4 f
Z
pH and EC of solution obtained by the pour through method.
3.7 h 0.6 b 3.7 g
Y
Days after transplanting.
X
WT = Whole Tree.
W
CPL = Composted poultry litter.
T
Means separated within column by Duncan's Multiple Range Test at P  = 0.05.
V
CCR = Clean chip residual.
 
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52
 
 
 
 
 
 
Substrate 120 DAT
U
340 DAT 120 DAT 340 DAT 120 DAT 340 DAT 120 DAT 340 DAT 120 DAT 340 DAT
6:1 WT
Y
:CPL
X
27.0 bcd
T
32.8 b 15.3 b 25.2 b 34.4 e 39.5 c 20.5 d 29.1 c 20.0 a 31.3 a
6:1 CCR
W
:CPL 32.3 a 35.8 ab 20.6 a 30.2 a 45.8 bc 46.4 b 19.8 d 31.6 bc 24.7 a 35.6 a
6:1 PB
V
:CPL 31.1 ab 36.2 ab 17.4 b 23.7 bc 37.3 de 40.7 c 21.1 cd 29.6 c 25.3 a 32.3 a
100% WT 28.8 abcd 36.7 a 14.7 cb 21.7 cd 45.1 c 46.4 b 23.0 bcd 33.7 b 25.6 a 35.1 a
100% CCR 29.4 abc 37.4 a 14.8 cb 19.2 de 53.3 a 53.2 a 27.3 a 39.4 a 25.6 a 35.9 a
100% PB 28.1 bcd 36.2 ab 12.4 c 16.5 e 41.8 cd 43.2 bc 24.8 ab 33.4 b 24.8 a 33.5 a
6:1 WT:Peat 26.0 cd 34.5 ab 15.1 bc 20.4 d 41.9 cd 42.6 bc 20.7 d 38.9 a 20.7 a 32.3 a
6:1 CCR:Peat 28.3 abcd 36.7 a 14.8 bc 19.5 de 51.2 ab 51.6 a 24.0 bc 37.9 a 24.6 a 32.4 a
6:1 PB:Peat 24.7 d 32.8 b 12.5 c 17.0 e 42.6 cd 44.1 bc 20.4 d 31.9 bc 24.2 a 41.0 a
Y
WT = Whole Tree.
Table 1.2 Experiment 1. Influence of substrate composition on growth indices
Z 
at 120 and 340 days after transplanting.
Z
Growth Indices = [(height + width1 + width2)/3]
X
CPL = Composted Poultry Litter.
V
PB = Pinebark.
U
DAT = Days after transplanting.
T 
Means separated using Duncan's Multiple Range Test at P  = 0.05.
W
CCR = Clean chip residual.
                Holly            Boxwood          Loropetalum             Azalea            Ternstroemia
 
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53
 
 
         
 
 
 
 
Treatment 60 DAT 120 DAT 60 DAT 120 DAT 60 DAT 120 DAT 60 DAT 120 DAT 60 DAT 120 DAT
6:1 WT
X
:CPL
W
4.0 a
T
4.0 a 3.9 ab 4.0 a 3.1 d 3.8 d 3.4 c 3.6 d 3.7 c 3.6 c
6:1 CCR
V
:CPL
4.0 a 4.0 a 4.0 a 4.0 a 3.8 bc 4.3 ab 3.5 c 3.8 d 3.8 bc 3.1 d
6:1 PB
U
:CPL
4.0 a 4.0 a 3.8 ab 4.0 a 3.9 b 4.3 ab 3.9 ab 3.8 d 3.8 bc 3.8 bc
100% WT      4.0 a 4.0 a 3.9 ab 4.0 a 3.8 bc 4.5 a 3.9 ab 4.2 bc 4.1 ab 4.4 a
100% CCR      4.0 a 4.0 a 3.9 ab 4.0 a 4.4 a 4.1 bc 4.2 a 4.5 ab 4.0 abc 4.0 abc
100% PB          4.0 a 4.0 a 3.4 c 4.0 a 3.6 c 3.9 cd 3.9 ab 3.9 cd 4.1 ab 4.1 ab
6:1 WT:Peat       4.0 a 4.0 a 3.9 a 4.0 a 3.6 c 4.1 bcd 4.1 a 4.8 a 3.8 bc 3.9 bc
6:1 CCR:Peat      4.0 a 4.0 a 3.9 ab 4.0 a 4.3 a 4.1 bcd 3.9 ab 4.2 bc 3.9 abc 3.9 bc
6:1 PB:Peat         4.0 a 4.0 a 3.6 bc 4.0 a 3.8 bc 3.4 e 3.9 ab 3.9 cd 4.2 a 4.0 abc
                  Ternstroemia
Table 1.3 Experiment 1. Influence of substrate composition on foliar color ratings
Z
 at 60 and 120 DAT
Y
.                         
                   Holly               Boxwood               Loropetalum                 Azalea
T
 Means separated using Duncan's Multiple Range Test at P  = 0.05.           
V
 CCR = Clean chip residual.
Z
 Foliar color rated on a scale of 1 to 5, 1 = severe chlorosis, 5 = dark green.
Y
 DAT = Days after transplanting.
X
WT = Whole Tree.
W
 CPL = Composted poultry litter.
U
 PB = Pinebark.
 
 
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54
 
 
 
 
 
                      
Treatment Holly Loropetalum Azalea 120 DAT
T
340 DAT
3.1 b
S
2.2 d 1.3 e 5.7 a 7.35 a
3.7 b 2.6 c 2.2 d 4.9 b 6.5 b
3.6 b 3.3 b 2.3 d 3.1 e 3.6 e
4.6 a 3.6 ab 3.4 c 3.7 cd 4.5 cd
4.8 a 3.9 a 4.3 ab 4.0 c 4.5 cd
4.6 a 3.6 ab 4.1 b 3.4 de 4.1 de
4.3 a 3.4 ab 4.1 b 4.1 c 4.8 c
4.7 a 3.6 ab 4.6 a 3.7 cd 4.3 cd
4.3 a 2.9 c 3.8 b 3.7 cd 4.3 cd
                            Root Ratings Shrinkage
6:1 CCR
V
:CPL            3.8 a 3.1 bc
Table 1.4 Experiment 1. Influence of substrate composition on root rating
Z 
and shrinkage
 Y
.
Boxwood Ternstroemia
6:1 WT
X
:CPL
W            
2.8 bc 2.3 c
6:1 PB
U
:CPL          3.1 b 3.8 bc
100% WT      2.4 c 4.2 a
100% CCR      2.7 bc 4.0 ab
100% PB          1.6 d 3.3 b
6:1 WT:Peat          2.3 c 3.2 bc
6:1 CCR:Peat        1.8 d 3.6 ab
6:1 PB:Peat          1.4 d 4.0 ab
Z
 Root rating scale of 1 to 5, 1 = very poor root system, 5 = very strong root system.
Y
 Shrinkage = measure (cm) from media surface to the top of pot.
X
 WT = Whole tree.
W
 CPL = Composted poultry litter.
V
CCR = Clean chip residual.
U
 PB = Pinebark.
T
 DAT = Days after transplanting.
S 
Means separated within column by Duncan's Multiple Range Test at P  = 0.05. 
 
 
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55
 
 
 
 
 
 
Table 1.5 Experiment 1. Tissue nutrient content of Ternstroemia gymnanthera .
Treatment        Tissue Nutrient Content
Z
N (%) P (%) K (%) Ca (%) Mg (%) Al (ppm) B (ppm) Fe (ppm) Mn (ppm) Na (ppm) Cu (ppm) Zn (ppm)
6:1 WT
Y
:CPL
X
1.5 bcde
U
0.18 bc 1.1 a 1.3 ab 0.34 ab 52.5 e 30.2 ab 36.2 a 27.6 c 438.8 abc 9.5 a 17.6 a
6:1 CCR
W
:CPL 1.3 de 0.17 bc 0.9 a 1.5 ab 0.34 ab 74.1 de 26.4 ab 54.8 a 29.2 c 448.4 abc 6.6 a 12.7 a
6:1 PB
V
:CPL 1.4 cde 0.23 a 1.0 a 1.7 ab 0.38 a 113.4 cd 37.5 a 54.8 a 55.3 ab 506.1 ab 11.7 a 22.9 a
100% WT 1.6 a 0.14 bc 1.0 a 1.2 b 0.33 ab 102.7 cd 20.7 b 41.3 a 37.0 bc 394.7 c 3.8 a 11.7 a
100% CCR 1.5 abc 0.12 bc 1.1 a 1.4 ab 0.34 ab 129.5 bc 22.2 b 34.9 a 54.0 ab 390.3 c 0.1 a 10.1 a
100% PB 1.4 abcd 0.17 bc 1.1 a 2.0 a 0.32 b 198.7 a 30.4 ab 49.9 a 54.6 ab 523.3 a 11.4 a 20.4 a
6:1 WT:Peat 1.6 ab 0.13 bc 1.0 a 1.6 ab 0.32 b 124.0 bc 23.4 b 38.9 a 34.9 c 459.5 abc 3.6 a 12.3 a
6:1 CCR:P 1.6 ab 0.20 ab 1.2 a 1.9 ab 0.30 b 166.1 ab 30.6 ab 44.9 a 59.8 a 514.7 ab 8.5 a 15.8 a
6:1 PB:P 1.3 e 0.11 c 0.9 a 1.6 ab 0.30 b 158.5 ab 21.0 b 44.4 a 36.3 bc 426.3 bc 22.5 a 12.4 a
Suffienciency range
T
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 ***
S
55-126 58-69 15-35 *** 4-6 7-10
Z
 Tissue analysis performed on 10 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently matured leaves) per plant; N = nitrogen, P = phosphorus,
K = potassium, Ca = Calcium, Mg = magnesium, Al = aluminum, B = boron, Fe = iron, Mn = manganese, Zn = zinc. 
Y
 WT = Who leTre e.
X
 CPL = Composted poultry litter.
W
 CCR = Clean chip residual.
V
 PB = Pinebark.
U
 Means separated within column by Duncan's Multiple Range Test (P  = 0.05).
T
 Sufficiency range published by Mills and Jones (1996).
 
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56
 
 
 
 
 
 
 
 
Air Space
X
Container capacity
W
Total porosity
V
Bulk density
U 
Treatments
Y
(%  Vol) (g-cm
3
)
6:1 WT:CPL
21 f
T
56 a 77 e 0.23 b
6:1 CCR:CPL 28 de 51 b 80 c 0.24 ab
6:1 PB:CPL 37 b 38 e 75 f 0.25 a
100% WT 26 e 55 a 80 bc 0.20 d
100% CCR 35 bc 47 c 82 b 0.20 d
100% PB 42 a 41 d 83 a 0.22 c
6:1 WT:Peat 27 de 57 a 83 a 0.20 d
6:1 CCR:Peat 29 d 45 c 74 f 0.17 e
6:1 PB:Peat 33 c 45 c 78 d 0.23 bc
30-Oct 45 - 65 50 - 85 0.19 - 0.70
U
Bulk density after forced-air drying at 105? C (221.0? F) for 48 h; 1 g cm3 = 62.4274 lb/ft3.
T
Means separated within column by Duncan's Multiple Range Test at P  = 0.05 (n=3).
S
Recommended ranges as reported by Yeager et al., 2007. Best Management Practices Guide for 
 producing Container-Grown Plants.
V
Total porosity is container capacity + air space.
W
Container capacity is (wet weight - oven dry weight) divided by volume of the sample.
Table 2.1 Physical properties of whole tree, pinebark, and clean chip residual based substrates
Z
.
Recommended range
S 
Y
WT = WholeTree, CCR=Clean chip residual, PB= pinebark, CPL=composted poultry litter.
X
Air space is volume of water drained from the sample divided by volume of the sample.
Z
Analysis performed using the North Carolina State University porometer.
 
 
 
                 
 
 
 
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57
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
U.S. Sieve 
standard opening
sieve no.
(mm)
Z
6:1 WT:CPL
6:1 CCR
W
:CPL
6:1 PB:CPL 100% WT      100% CCR 100% PB      6:1 PB:Peat
1/2 12.5
0.0 c
X
0.0 c 2.8 b 0.0 c 0.0 c 5.0 a 5.6 a
3/8 9.5 0.0 c 0.0 c 3.8 b 0.0 c 0.0 c 3.8 b 6.1 a
1/4 6.35 1.6 c 1.9 c 9.2 b 0.4 c 0.3 c 11.3 a 10.2 ab
6 3.35 15.0 c 17.8 bc 20.2 ab 10.8 d 16.5 c 21.6 a 21.0 ab
8 2.36 18.8 b 19.5 b 12.5 c 19.5 b 20.7 b 12.7 c 10.6 c
10 2 6.9 c 7.7 bc 4.5 d 10.1 a 9.0 ab 4.4 d 3.6 d
14 1.4 17.0 bc 19.7 a 11.5 d 18.8 ab 18.4 ab 11.0 d 8.9 e
18 1 12.8 a 12.0 ab 9.5 c 12.3 ab 13.1 a 8.3 c 6.9 d
35 0.5 15.0 ab 12.0 bc 14.8 ab 13.5 abc 13.0 abc 12.6 abc 11.9 bc
60 0.25 7.0 ab 5.2 ab 6.7 ab 5.6 ab 5.2 ab 6.4 ab 8.8 a
140 0.11 3.1 ab 2.3 b 2.1 b 3.3 ab 1.9 b 2.1 b 5.1 a
270 0.05 1.0 ab 0.87 ab 0.50 b 0.70 ab 0.40 b 0.50 b 1.3 a
pan 0 0.43 ab 0.50 a 0.37 ab 0.23 ab 0.13 b 0.37 ab 0.43 ab
Texture
W
    Coarse 16.6 c 19.7 c 36.0 b 11.2 d 16.9 c 41.6 a 42.6 a
    Medium 55.6 bc 58.8 ab 38.0 d 60.8 ab 61.2 a 36.4 d 30.0 e
    Fine 58.6 c 62.8 bc 43.0 d 66.8 ab 68.2 ab 44.4 d 41.0 d
Substrates
Y
Table 2.2 Experiment 2. Particle size analysis of substrates.
6:1 WT:Peat       6:1 CCR:Peat
0.0 c 0.0 c
0.0 c 0.1 c
0.8 c 1.1 c
20.4 ab 16.7 c
25.4 a 18.4 b
75 bc 7.2 c
16.7 bc 15.5 c
11.1 b 11.9 ab
10.7 c 15.6 a
4.6 b 8.1 ab
1.6 b 3.7 ab
0.43 b 0.80 ab
0.47 a 0.33 ab
Y
 WT= Whole Tree, CPL = Composted poultry litter, CCR = Clean Chip Residual, PB = Pinebark.
21.2 c 17.9 c
60.7 ab 53.0 c
69.7 a 63.0 bc
Z
 1 mm = 0.0394 in.
X
 Percent weight of sample collected on each screen, means within row followed by the same letter are not significantly different based on Duncan's  Multiple Range 
W
 Coarse = 3.35-12.5 mm; Medium = 1.00-2.36 mm; Fine = 0.00-0.50 mm.
Test at (P  = 0.05).
 
 
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58
 
 
 
 
Table 2.3.  Experiment 2. Solution pH and electrical conductivity (EC) of substrates
Z
.
Treatment pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m)
6:1 WT
X
:CPL
W
7.4 a
T
3.9 a 7.3 a 0.8 b 6.6 a 0.7 cd 6.8 a 0.46 bc 6.5 a 0.28 a 5.7 a 0.16 b 5.5 a 0.14 c
6:1 CCR
V
:CPL
7.4 a 2.9 b 7.1 a 0.7 b 6.5 a 0.9 bc 6.3 b 0.73 a 6.3 a 0.24 ab 6.0 a 0.12 cd 5.2 b 0.14 c
6:1 PB
U
:CPL
6.9 b 2.8 b 6.5 b 1.3 a 5.8 bc 1.3 a 5.7 c 0.48 b 5.3 b 0.21 abc 5.0 b 0.16 b 4.1 c 0.21 ab
100% WT 5.5 c 1.0 cd 6.3 c 0.5 cd 6.0 b 0.6 cd 5.1 de 0.37 bcd 4.5 bc 0.18 bcd 3.3 d 0.16 bc 3.1 e 0.23 ab
100% CCR 4.8 d 0.7 cd 5.8 d 0.3 d 5.9 b 0.4 d 5.2 d 0.27 d 4.3 c 0.17 bcd 3.4 d 0.16 bc 3.0 e 0.26 a
100% PB 4.2 f 0.5 d 4.8 f 0.5 cd 5.3 cd 0.7 bcd 4.8 e 0.28 d 4.3 c 0.14 cd 3.5 cd 0.17 b 3.3 de 0.22 ab
6:1 WT:Peat 4.6 e 0.9 cd 5.8 d 0.3 d 5.7 bc 0.4 d 5.6 c 0.22 d 5.2 b 0.11 d 3.8 c 0.12 d 3.5 d 0.18 bc
6:1 CCR:Peat 4.1 fg 1.2 c 5.5 e 0.5 c 5.5 bcd 0.9 bc 4.8 e 0.31 cd 4.5 c 0.17 bcd 3.3 d 0.22 a 3.2 de 0.23 ab
6:1 PB:Peat 4.0 g 0.9 cd 4.6 f 0.5 c 5.1 d 1.0 ab 5.0 de 0.37 bcd 4.4 c 0.13 cd 3.7 cd 0.15 bcd 3.3 de 0.23 ab
Z
pH and EC of solution obtained by the pour through method.
Y
Days after transplanting.
X
WT = Whole Tree.
W
CPL = Composted poultry litter.
V
CCR = Clean chip residual.
U
PB = Pinebark.
T
Means separated within column by Duncan's Multiple Range Test at P  = 0.05.
       7  DAT
Y
   30 DAT     60 DAT   120 DAT  90 DAT 285 DAT 390 DAT
 
 
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59
 
 
 
 
 
 
 
 
 
Table 2.4  Experiment 2. Influence of substrate composition on growth indices
Z 
at 60 and 390 days after transplanting.
60 DAT
U
390 DAT 60 DAT 390 DAT 60 DAT 390 DAT 60 DAT 390 DAT 60 DAT 390 DAT
26.0 c
T
40.3 c 18.5 ab 31.1 a 42.4 ab 50.0 a 24.8 bc 33.3 d 30.4 abc 39.2 dc
30.4 b 43.5 bc 17.2 ab 30.4 a 38.1 b 54.4 a 25.5 bc 34.2 d 26.5 c 37.6 d
35.8 a 48.6 a 18.8 ab 27.5 b 37.9 b 52.7 a 26.7 bc 37.8 c 30.5 abc 45.3 bc
32.3 b 45.1 b 18.5 ab 26.5 b 43.5 ab 37.7 bc 29.2 ab 45.9 a 29.5 bc 47.2 ab
32.2 b 43.4 bc 16.9 b 23.6 cd 37.8 b 36.2 bc 23.5 c 42.0 b 27.7 c 44.1 bc
31.1 b 41.7 bc 18.0 ab 23.0 d 47.6 a 50.4 a 31.0 a 45.5 ab 30.6 abc 45.5 bc
29.3 b 41.1 c 18.6 ab 26.0 bc 43.7 ab 41.4 b 31.0 a 46.6 a 34.3 a 52.3 a
29.2 b 44.2 bc 25.7 a 24.0 cd 41.6 ab 34.9 c 27.5 abc 43.7 ab 31.1 abc 47.6 ab
31.8 b 40.3 c 17.9 ab 23.4 cd 48.0 a 49.2 a 31.1 a 44.1 ab 33.2 ab 50.1 ab
U
DAT = Days after transplanting.
T
Means separated using Duncan's Multiple Range Test at P = 0.05.
100% CCR
100% WT
6:1 PB
V
:CPL
6:1 CCR
W
:CPL
6:1 WT
Y
:CPL
X
Substrate
Ternstroemia
6:1 PB:Peat
6:1 CCR:Peat
6:1 WT:Peat
100% PB
Y
WT = Whole Tree.
Z
Growth Indices = [(height + width1 + width2)/3]
X
CPL = Composted Poultry Litter.
W
CCR = Clean chip residual.
V
PB = Pinebark.
Holly Boxwood Loropetalum Azalea
 
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60
 
 
 
 
 
 
 
 
Table 2.5.  Influence of substrat e composi tition on foliar color ratings
Z
 at 60, 120, and 390 DAT
Y
.                                                       
Holly Boxwood Loropetalum Azalea Ternstroemia
Treatment 60 DAT 120 DAT 390 DAT 60 DAT 120 DAT 390 DAT 60 DAT 120 DAT 390 DAT 60 DAT 120 DAT 390 DAT 60 DAT 120 DAT 390 DAT
6:1 WT
X
:CPL
W
4.0 a
T
4.0 a 4.1 bc 3.3 abc 3.9 a 3.9 ab 3.3 cd 4.1 c 3.9 a 3.3 bc 3.3 cd 4.0 a 3.6 b 3.1 c 3.8 c
6:1 CCR
V
:CPL
4.0 a 4.0 a 4.4 a 3.0 c 4.0 a 4.0 a 3.1 d 4.2 c 2.9 a 3.1 c 3.1 d 4.0 a 3.6 b 3.0 c 4.1 abc
6:1 PB
U
:CPL
4.0 a 4.0 a 4.3 ab 3.6 a 4.0 a 3.7 a 3.9 bc 4.6 abc 3.1 a 4.0 ab 3.8 bcd 4.0 a 3.6 b 3.8 b 3.9 bc
100% WT      4.0 a 4.0 a 4.4 a 3.5 ab 4.0 a 3.8 ab 4.4 ab 5.0 a 2.8 a 3.6 abc 4.4 ab 4.0 a 3.9 a 4.0 a 4.4 a
100% CCR      4.0 a 4.0 a 4.4 a 3.2 bc 3.9 a 3.7 ab 3.7 cd 4.9 ab 3.4 a 3.2 c 3.8 abc 3.5 a 3.9 a 4.1 a 4.4 a
100% PB          4.0 a 4.0 a 4.4 a 3.7 a 4.0 a 3.8 ab 4.6 a 4.3 bc 2.8 a 4.3 a 4.5 a 4.0 a 4.2 a 4.0 a 3.9 bc
6:1 WT:Peat        
4.0 a 4.0 a 4.3 abc 3.4 abc 3.9 a 3.7 ab 4.6 a 5.0 a 3.0 a 4.3 a 4.6 a 4.0 a 4.2 a 4.1 a 4.2 ab
6:1 CCR:Peat       4.0 a 4.0 a 4.5 a 3.5 ab 4.0 a 3.6 b 4.6 a 5.0 a 2.6 a 3.8 abc 4.6 a 4.0 a 4.1 a 4.0 a 4.0 bc
6:1 PB:Peat          4.0 a 4.0 a 4.1 c 3.2 bc 4.0 a 3.6 b 4.6 a 5.0 a 3.3 a 3.8 abc 4.6 a 4.0 a 4.1 a 4.0 a 4.1 abc
Z
 Foliar color rated on a scale of 1 to 5, 1 = severe chlorosis, 5 = dark green.
Y
 DAT = Days after transplanting.
X
WT = Whole Tree.
W
 CPL = Composted poult ry litt er.
V
 CCR = Clean chip residual.
U
 PB = Pinebark.
T
 Means separated using Duncan's Multiple Range Test at P  = 0.05.           
 
 
 
 
 
 
 
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61
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Root Rating 
Treatment Holly Boxwood Loropetalum Azalea Ternstroemia
3.8 c
T
7.1 a 2.5 e 1.0 d 2.4 e
6.3 b 6.1 ab 3.3 de 0.9 d 2.0 e
7.6 ab 5.5 bc 5.1 ab 3.4 c 4.5 d
9.1 a 5.0 c 4.3 bcd 7.9 a 7.3 abc
8.8 a 3.6 de 4.8 abc 5.9 b 7.5 ab
8.1 a 2.9 ef 6.0 a 7.4 a 6.0 c
7.8 ab 4.6 cd 3.8 cde 6.6 ab 8.1 a
7.6 ab 3.8 de 3.3 de 7.5 a 7.9 ab
8.1 a 2.3 f 4.9 abc 7.9 a 6.6 bc
Z
 Root rating on scale of 0-10, 0 = 0% root coverage of rootball, 10 = 100% root coverage of rootball at 409 
after transplanting.
T
 Means separated using Duncan's Multiple Range Test at P  = 0.05
Y
 WT = Whole tree.
Table 2.6 Experiment 2 Influence of substrate composition on root ratings
 Z
.
6:1 WT
Y
:CPL
X           
6:1 CCR
V
:CPL            
6:1 PB
V
:CPL          
100% WT      
X
 CPL = Composted poultry litter.
W
CCR = Clean chip residual.
V
 PB = Pinebark.
U
 P = Peat.          
100% CCR      
100% PB          
6:1 WT:P
U         
6:1 CCR:P        
6:1 PB:P          
 
 
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62
 
 
 
 
 
 
 
 
 
 
 
 
Treatment
7 DAT
U
30 D AT 60 DAT 390 D AT
2.5 ab
T
3.3 a 4.9 a 6.4 a
2.1 cd 3.0 ab 4.6 a 5.7 b
1.9 e 2.2 c 2.9  d 2 .9 f
2.6 a 3.0 ab 3.7 b 4.6 c
2.3 cd 2.5 cd 3.3 bcd 3.5 de
2.3 bc 2.5 bc 3.1 cd 3.0 ef
2.5 ab 3.2 a 3.6 bc 3.8 d
1.8 e 2.3 c 3.0  d 3.3  def
2.0 de 2.4 bc 3.0 d 2.8 f
Z
 Shrinkage = measure (cm) from media surface to the top of pot.
100% CCR      
100% PB          
6:1 WT:Peat    
Shrinkage (cm)
6:1 WT
Y
:CPL
X            
6:1 CCR
V
:C P L            
6:1 PB
V
:CP L           
100% WT      
Table 2.7 Experiment 2. Influence of substrate composition on shrinkage
Z
.
6:1 CCR:Peat        
U
 DAT = Days after transplanting.
T 
M eans separated using Duncan's Multiple Range Test at P  = 0.05. 
Y
 WT = Whole tree.
X
 CPL = Composted poultry litter.
W
CCR = Clean chip residual.
V
 PB = Pinebark.
6:1 PB:Peat          
 
?
63
 
 
 
 
64 
 
 
 
 
 
 
 
CHAPTER III  
 
Application of Composted Poultry Litter as a Fertilizer for Landscape Use 
 
Abstract 
 Each year, over 16 million tons of poultry litter is produced in the U.S. and 
poultry farmers face the challenge of storing and disposing of poultry litter due to new 
federal and state regulations that limit the amount of poultry litter than can be land-
applied each year.  As a result, poultry farmers are looking for new avenues to dispose of 
this waste.  In this study, three experiments were conducted to evaluate use of composted 
poultry litter (CPL) as fertilizer for landscape annual bedding plants.  In experiments 1 
and 2, ?Celebrity Red? petunia and ?Quartz Scarlet? verbena were planted in raised beds 
simulating an urban landscape.  Prior to planting, 10 fertilizer or CPL treatments were 
incorporated into the raised beds including: Peafowl
?
 brand garden grade fertilizer 13N-
5.6P-10.9K (13-13-13) at rates of 4.9 g N/m
2 
(1 lb N/1000 ft
2
) and 9.8 g N/m
2 
(2 lb 
N/1000 ft
2
), Polyon
?
 13N-5.6P-10.9K (13-13-13) at rates of 4.9 g N/m
2 
(1 lb N/1000 ft
2
) 
and 9.8 g N/m
2 
(2 lb N/1000 ft
2
) and composted poultry litter at rates of 4.9 g N/m
2 
(1 lb 
N/1000 ft
2
), 9.8 g N/m
2 
(2 lb N/1000 ft
2
), 19.6 g N/m
2 
(4 lb N/1000 ft
2
), 29.4 g N/m
2 
(6 lb 
N/1000 ft
2
), 39.2 g N/m
2 
(8 lb N/1000 ft
2
), and 49 g N/m
2 
(10 lb N/1000 ft
2
).  Experiment 
3 was similar to experiments 1 and 2: however in experiment 3, Dusty Miller (Senecio 
cineria) was substituted for ?Quartz Scarlet? verbena.  Use of CPL incorporated into 
 
65 
 
 
landscape planting beds as a fertilizer source resulted in plants equal to or larger than 
plants grown with conventional inorganic fertilizers.  Nitrate and ammonia levels in 
leachates from plots amended with CPL were comparable with plots amended with 
commercial inorganic fertilizers and nitrogen (N) levels were in most cases less in plots 
fertilized with CPL when compared to inorganic fertilizers when the same N rate was 
applied.  CPL may not be able to replace inorganic fertilizers completely in all landscape 
situations, but it can reduce fertilizer requirements, and provide an economically and 
environmentally sound alternative to poultry waste disposal while providing beneficial 
aspects for plant growth in annual bedding plants. 
 
Introduction 
 The U.S. poultry and egg industry is valued at billions of dollars in gross farm 
receipts and employs hundreds of thousands of people.  In Alabama alone, the poultry 
industry generates over $2 billion in gross farm receipts and employs over 78,000 people 
(USDA, 2008).  Over the past several decades the poultry industry has expanded 
exponentially.  Increasing demand for low cholesterol meat products along with the 
recent cost saving changes in the farming industry from small family farms to large 
commercial farming practices have attributed to this expansion (Moore et al., 1996).   
Historically, poultry wastes have been used as a source of fertilizer and soil 
amendment in agronomic row cropping systems.  Poultry litter is often desired over other 
animal manures due to its high nutrient content in comparison with other animal manures.  
Typical poultry litter will have the following nutrient ranges: Nitrogen from 2.1 to 6%, 
Phosphorus from 1.4 to 9%, Potassium from 0.8 to 6.2%, Calcium from 0.8 to 6.1% 
 
66 
 
 
Magnesium from 0.2 to 2.1%, and Sulfur from 0.1 to 0.8%, on a dry-weight basis 
(Mitchell et al., 1995). 
While land application was the predominate disposal method for poultry litter in 
the past, due to increased environmental awareness, poultry litter is now under strict new 
state and federal regulations concerning disposal methods with respect to non-point 
source pollution and other environmental concerns.  In 1974 Congress passed the Safe 
Drinking Water Act which requires EPA to determine safe levels of chemicals in 
drinking water which do or may cause health problems.  These safe levels of 
contaminates are based solely on possible health risks and exposure, and are called 
Maximum Contaminant Level Goals (MCLGs).  The MCLG for NO
3
 has been set at 10 
mg/L (10 ppm) and the MCLG for NH
4
 at 0.5 mg/L (0.5 ppm) (EPA, 1972).  Based upon 
these MCLGs, EPA has set an enforceable standard called a Maximum Contaminant 
Level (MCL).  Beginning in 1993, EPA requires water suppliers to collect water samples 
at least once a year and determine if NO
3
 or NH
4
 water levels are present above 50 
percent of their MCLs.  If N levels are present above these levels, the system must 
continue to monitor the contaminant every three months, and consequently take steps to 
reduce the amount of N in water supplies.  Approximately 44% of Alabamians obtain 
drinking water from ground-water supplies (Hairston and Stribling, 1995).  Because 
leached nitrate-N from landscape fertilization programs can contaminate drinking water, 
it is important to identify landscape fertilization practices that provide excellent plant 
growth while minimizing N lost to leaching. 
  While new regulations are placing limits on land application of poultry litter, a 
fair amount of poultry litter can still be land applied; however, management of available 
 
67 
 
 
lands for application is now becoming a problem.  As populations continue to grow, rural 
areas are declining in size as cities are expanding to meet population needs.  As a result, 
there are fewer acres of agricultural land for spreading manure (Wolfe and Humphries, 
2007).  Expansion of cities and population increases could present a new avenue for 
poultry litter disposal in the landscape and soilless potting media industry.  In Alabama, 
greenhouse, nursery, and landscape operations employed 44,000 people and had a $2.89 
billion economic impact in the state in 2008 (J. Harwell, pers. comm.).  The horticulture 
industry is now the fastest growing sector in agriculture in Alabama and with more and 
more landscape and nursery operations in business, poultry producers are turning to the 
green industry as a means of disposing excess manure.  Research is underway to find 
alternative uses for composted poultry litter in different agricultural sectors and to 
establish areas where poultry litter could provide the best economic and environmental 
benefit. 
Considering the high nutrient content of poultry litter and the accessibility of the 
product, especially in the intense production areas of the southeastern United States, 
horticulture professionals, farmers, and turfgrass managers are turning to poultry litter 
and other organic sources as an alternative to costly inorganic fertilizer sources.  
Inorganic fertilizer cost is increasing while U.S. fertilizer production is decreasing.  
Because natural gas is the primary raw material used to produce ammonia, the rise in 
U.S. gas prices has led to a 35% decline in U.S. ammonia production capacity and a 44% 
decrease in output between years 2000 and 2006.  National average fertilizer prices 
increased 113% between 2000 and 2007 due to increases in nitrogen costs.  During this 
seven year period, the price of ammonia, the main source of nitrogen in fertilizer 
 
68 
 
 
production, increased 130% and the price of urea, the primary solid nitrogen fertilizer 
used in the U.S. rose 127% (Wen-yuan, 2007).  Due to the increases in inorganic 
fertilizer sources, the nutrients in poultry litter are more valuable than ever.   
There is a great potential for the use of organic manure type products in the 
landscape and homeowner sector.  Increased awareness of environmental impacts from 
the use and manufacture of inorganic fertilizer sources has caused many homeowners to 
seek more environmentally friendly products.  Organically based products are becoming 
more popular, especially with urban consumers. Recent trends such as ?Going Green? 
have made the use of organic products more desirable and marketable. 
 Many studies have been conducted showing the benefits of poultry litter 
application as a fertilizer in row cropping systems (Burmester et al., 1991; Porch et al., 
1990).  Poultry litter has also been shown to improve growth in roses, woody 
ornamentals, annuals, and bermuda grass production (Feagley et al., 2005; Reeder et al., 
1992; Warren and Safley, 1990).  In two studies by Altland (2002) growth of ?Magestic 
Giants White? pansy (Viola x wittrockiana) and Telstar Purple dianthus (Dianthus 
chinensis) was compared when fertilized with granular water soluble fertilizers (GWS), 
controlled release fertilizers (CRF), and an organically based fertilizer (OBF) composed 
of recycled newspaper amended with poultry litter at similar rates.  In experiment 1, the 
OBF resulted in plants having adequate foliar color and plant size, with less total nitrogen 
leaching recovered from soil water samples.  In experiment 2, plants fertilized with OBF 
in general had superior foliar color and size compared to all other treatments, but also 
caused elevated levels of total nitrogen in soil water.  However, composting poultry litter 
prior to application could reduce nitrogen leaching.  Use of poultry litter in the landscape 
 
69 
 
 
industry could provide an environmentally sound means of disposal for poultry producers 
as well as an economical alternative to increasingly expensive fertilizers.   
Research is needed to understand how the type of fertilizer used will affect plant 
growth and nutrient leaching.  The objective of this study was to evaluate composted 
poultry litter as a fertilizer source for bedding plants at various rates in comparison with 
commercially available inorganic fertilizers for three commonly used landscape annual 
bedding species, ?Quartz Scarlet? verbena, ?Celebrity Red? petunia, and Dusty Miller 
(Senecio cineraria) in regards to plant growth and nutrient leaching.  In order to evaluate 
consecutive applications of CPL to the same area, each plot received the same fertilizer in 
each of the three experiments. 
 
Materials and Methods 
Experiment 1 
 A fallow site was chosen which had not received any fertilizer in several years.  
Plots were tilled to a 10.2 cm (4 in) depth and raised beds were developed using a Kenco 
bed maker (Kenco Corp., Ligonier Valley, PA) with each experimental unit being 3.05 m 
by 0.46 m (10 ft by 1.5 ft).  Before planting 10 treatments were applied: Peafowl
?
 brand 
(Piedmont Fertilizer Co., Opelika, AL) garden grade fertilizer 13N-5.6P-10.9K (13-13-
13) at rates of 4.9 g N/m
2 
(1 lb N/1000 ft
2
) and 9.8 g N/m
2 
(2 lb N/1000 ft
2
), Polyon
?
 
(Agrium Advanced Technologies, Sylacauga, AL) 13N-5.6P-10.9K (13-13-13) at rates of 
4.9 g N/m
2 
(1 lb N/1000 ft
2
) and 9.8 g N/m
2 
(2 lb N/1000 ft
2
) and composted poultry litter 
(CPL) at rates of 4.9 g N/m
2 
(1 lb N/1000 ft
2
), 9.8 g N/m
2 
(2 lb N/1000 ft
2
), 19.6 g N/m
2 
 
70 
 
 
(4 lb N/1000 ft
2
), 29.4 g N/m
2 
(6 lb N/1000 ft
2
), 39.2 g N/m
2 
(8 lb N/1000 ft
2
), and 49 g 
N/m
2 
(10 lb N/1000 ft
2
).  A control receiving no fertilizer was also maintained for 
comparison.  Treatments were top-dressed on the prepared landscape beds and lightly 
tilled in prior to planting.  Poultry litter used in this experiment was obtained from 
Greenville, AL. and was composted in an in-vessel rotating drum digester (BW Organics, 
Sulphur Springs, TX) for two weeks and stored under a tarp for 30 days until installation 
of the study.  Poultry litter was analyzed by Brookside Laboratories Inc. (New Knoxville, 
OH).  Composted poultry litter analysis showed 2.5% nitrogen, 1.4% phosphorous, and 
2.3% potassium on a wet weight (as is) basis. On August 17, 2007 fertilizer treatments 
were applied to the raised beds and Petunia spp. ?Celebrity Red? and Verbena hybrida 
?Quartz Scarlet? were transplanted from 36 cell-pack liners into the prepared landscape 
beds.  In each plot, 12 plants of one species were planted 0.3 m (1 ft) on center.  Plants 
were arranged by species in a randomized complete block design.  Soil water leachates 
were collected using suction cup lysimeters 0.6 m (2 ft) long and 5.1 cm (2 in) in 
diameter with a ceramic cap 7.6 cm (3 in) long and 5.1 cm (2 in) wide.  Lysimeters were 
installed at a 45? angle to the ground to minimize preferential water flow down the side of 
the lysimeter at a depth of 25.4 cm (10 in).  The hole for the lysimeter was formed using 
a soil core remover.  A mud slurry using soil from the hole was poured back into the hole 
before insertion of the lysimeter to ensure soil contact with the ceramic cap.  A hand 
pump was used to create a suction of 60 centibars (8.82 psi) within the lysimeter.   
 Data collected included growth indices [(height +width1 + width 2)/3(cm)] at 4, 
8, and 12 weeks after planting (WAP). Leaf chlorophyll content (LCC) was quantified 
 
71 
 
 
using a SPAD-502 Chlorophyll Meter (Minolta, Inc.) at 4, 8, and 12 WAP.  Plants were 
harvested at 12 WAP to avoid potential frost injury.  Leachates were collected using 
lysimters at 2, 4, 8, 12, and 16 WAP.  Soil water collected from lysimeters was analyzed 
using a colorimetric procedure to determine N as NO
3
 and NH
4
.  Water was also analyzed 
for pH, electrical conductivity (dS/m). Fresh and dry weights were taken 12 WAP.  Foliar 
samples (most recently matured leaves) (Mills and Jones, 1996) were collected and 
analyzed for nutrient content at 12 WAP.  Foliar samples were analyzed for nitrogen (N), 
phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), iron (Fe), 
manganese (Mn), copper (Cu), zinc (Zn), aluminum (Al), cadmium (Cd), chromium (Cr), 
sodium (Na), nickel (Ni), lead (Pb), and carbon (C).  Foliar N was determined by 
combustion analysis using a 1500 N analyzer (Carlo Erba, Milan, Italy).  Remaining 
nutrients were determined by microwave digestion with inductively coupled plasma-
emission spectrometry (Thermo Jarrel Ash, Offenbach, Germany).  Data were analyzed 
using Duncan?s Multiple Range Test (P < 0.05) using a statistical software package 
(SAS
?
 Institute version 9.1, Cary, NC). 
 
Experiment 2 
Experiment 2 was similar to experiment 1 with the following exceptions:  On May 19, 
2008, fertilizer treatments were applied to the raised landscape beds as mentioned in 
experiment 1.  Poultry litter used experiment 2 was obtained from Greenville, AL. and 
was composted in an in-vessel rotating drum digester (BW Organics, Sulphur Springs, 
TX) for two weeks.  Poultry litter was analyzed by Brookside Laboratories Inc. (New 
Knoxville, OH).  Composted poultry litter analysis showed 2.3% nitrogen, 1.5% 
 
72 
 
 
phosphorous, and 2.3% potassium on a wet weight (as is) basis.  Petunia spp. ?Celebrity 
Red? and Verbena hybrida ?Quartz Scarlet? were transplanted from 36 cell-pack liners 
into the prepared landscape beds on May 19, 2008, similarly to experiment 1. Eight 
plants of either petunia or verbena were planted per plot and each species analyzed 
separately.  Leachates were collected using lysimters at 1, 2, 4, 8, and 12 WAP.  Soil 
water collected from lysimeters was analyzed using a colorimetric procedure to 
determine N as NO
3
 and NH
4
.  Water was also analyzed for pH, electrical conductivity 
(dS/m). Fresh and dry weights were taken 12 WAP.  Foliar samples (most recently 
matured leaves) (Mills and Jones, 1996) were collected and analyzed for nutrient content 
at 12 WAP.  Foliar samples were analyzed for nitrogen (N), phosphorous (P), potassium 
(K), calcium (Ca), magnesium (Mg), boron (B), iron (Fe), manganese (Mn), copper (Cu), 
zinc (Zn), aluminum (Al), and sodium (Na).  Foliar N was determined by combustion 
analysis using a 1500 N analyzer (Carlo Erba, Milan, Italy).  Remaining nutrients were 
determined by microwave digestion with inductively coupled plasma-emission 
spectrometry (Thermo Jarrel Ash, Offenbach, Germany).   Data were analyzed as in 
experiment 1. 
 
Experiment 3 
Experiment 3 was similar to experiments 1 and 2 with the following exceptions:  On 
August 21, 2008, fertilizer treatments were applied to raised landscape beds as mentioned 
in experiment and Petunia spp. ?Celebrity Red? and Senecio cineria (Dusty Miller) were 
transplanted from 36 cell-packs into the prepared landscape beds.  Eight plants petunia 
and dusty miller were planted per plot and each species analyzed separately.  CPL was 
 
73 
 
 
taken from the same source as CPL used in experiment 2 and nutrient analysis of CPL 
was the same as in experiment 2.  Data was taken and analyzed as in experiments 1 and 2. 
 
Results 
Experiment 1 
Growth indices (GI) and Dry weights (DW).  At 4 WAP, petunia growth was similar 
among the Peafowl brand (9.8 g N/m
2
), Polyon (9.8 g N/m
2
), CPL (9.8 g N/m
2
), CPL 
(19.6 g N/m
2
), CPL (29.4 g N/m
2
), CPL (39.2 g N/m
2
), and CPL (49.0 g N/m
2
) (Table 
1.1).  By 8 WAP CPL (29.4 g N/m
2
), CPL (39.2 g N/m
2
), CPL (49.0 g N/m
2
) and 
Peafowl brand (9.8 g N/m
2
) had the highest GI, however Peafowl (9.8 g N/m
2
) and CPL 
(29.4 g N/m
2
), and CPL (49.0 g N/m
2
) were similar to other treatments, except Peafowl 
and Polyon (at 4.9 g N/m
2
) and the non-fertilized control.  At 12 WAP CPL treatments 
(29.4, 39.2, and 30.7 g N/m
2
) along with Polyon (9.8 g N/m
2
) had the largest GI.  The 
increased growth in beds with Polyon fertilizer treatment at 12 WAP may be due to the 
extended release of the product over time.  In addition, when CPL was compared with 
either Peafowl or Polyon fertilizer at the same fertilizer rate, CPL grew petunias as large 
as or larger than the inorganic fertilizers at all dates GI was taken.   
 Petunia dry weights (DW) generally increased as fertilizer rate increased (Table 
1.1).  As expected, petunia DW revealed that petunias grown in CPL plots had similar 
DW to petunias grown with Peafowl or Polyon fertilizers when the same N rate of 
fertilizer was applied. 
 Verbena GI revealed little differences in GI at 4 WAP and 8 WAP (Table 1.1).  
However, by 12 WAP, Peafowl (9.8 g N/m
2
) and both Polyon rates along with CPL 
 
74 
 
 
treatments (29.4, 39.2, and 49.0 g N/m
2
) had the largest GI.  Again, growth of verbena 
was statistically similar in plots treated with CPL and inorganic fertilizers at the same N 
rate.  Verbena DW generally increased as fertilizer rate increased (Table 1.1) with the 
exception of Polyon treatments, and verbena fertilized with CPL at 4.9 g N/m
2
 had higher 
DW than verbena fertilized with CPL at 9.8 g N/m
2
, however these two treatments were 
statistically similar.  While the higher rates of CPL (39.2 and 49.0 g N/m
2
) had the higher 
verbena DW, these DWs were statistically similar to other treatments.  Again, when the 
same N rate of fertilizer was used, plants grown with CPL were similar to plants grown 
with inorganic fertilizers. 
 
Leaf chlorophyll content (LCC).  At 4 WAP there were no differences in leaf chlorophyll 
content (LCC) of petunia in any treatment (Table 1.2).  At 8 WAP, plants in CPL (49.0 g 
N/m
2
) had the highest LCC, however LCC was statistically similar for plants in both rates 
of Peafowl brand, both rates of Polyon, as well as CPL at 39.2 g N/m
2
.  By 12 WAP, 
there were very few differences in LCC among treatments.  Peafowl (9.8 g N/m
2
), Polyon 
(4.9 g N/m
2
), along with CPL at rates of 29.4, 39.2, and 49.0 g N/m
2
  were slightly higher 
than other treatments, however plants in these treatments were still statistically similar to 
most other treatments. 
 At 4 WAP, there were no differences in LCC of verbena.  At 8 WAP, plants in 
CPL treatments 4.9 g N/m
2
, 9.8 g N/m
2
, and 19.6 g N/m
2 
had slightly lower LCC than 
other treatments, however by 12 WAP no differences were observed. 
 
 
75 
 
 
Tissue Nutrient Content.  In general, petunia tissue nutrient content was similar among all 
treatments for N, with Peafowl (4.9 g N/m
2
) having slightly less foliar N and Polyon (9.8 
g N/m
2
) having slightly more (Table 1.3).  P tended to be highest in CPL treatments 
(29.4, 39.2, and 49.0 g N/m
2
).  No differences were observed in K among any treatment.  
All other essential nutrients were equal to or above sufficiency ranges, with the exception 
of B, which was slightly less than the sufficiency range, and Cd and Cr were higher in 
CPL at 19.6 g N/m
2
 than any other treatments (Mills and Jones, 1996). 
 There were no differences in foliar N content of verbena (Table 1.4).  Again, P 
tended to be highest in treatments fertilized with CPL at rates of 39.2 and 49.0 g N/m
2
.  K 
content was highest in verbena fertilized with Peafowl fertilizer (4.9 g N/m
2
), however 
foliar K content was similar to both rates of poly and CPL at 9.8, 29.4, 39.2, and 49.0 g 
N/m
2
).  All other essential nutrients were within or above sufficiency levels (Mills and 
Jones, 1996).  As in petunia, verbena Cd and Cr levels were highest in CPL at 19.6 g 
N/m
2
 than in any other treatment. 
 
N levels in soil-water as NO
3
 - N and NH
4
 ? N.  At 2 WAP, NO
3
 and NH
4 
were high for 
all treatments (Table 1.5).  No treatment was less than 6 times the EPA recommended 
level for NO
3
 in drinking supplies (10 mg/L or 10 ppm) and only the non-fertilized 
control was close to having an acceptable NH
4
 level of 0.5 mg/L (0.5 ppm) (EPA, 1972).  
At 4 WAP NO
3
 levels remained high; NH
4 
levels began to drop and no differences were 
observed among any treatment with the exception of Peafowl (9.8 g N/m
2
) which was 
significantly higher than all other treatments, a trend that continued at 8 WAP.  NO
3
 at 8 
weeks, however, dropped significantly from previous levels and all treatments were 
 
76 
 
 
within acceptable levels with the exception of the Peafowl fertilizer at both treatments 
which remained high.  By 12 WAP, NO
3
 and NH
4
 levels were within recommended 
levels and remained within these recommended levels for the duration of the study.  
While all treatments were within recommended levels, Polyon at the 9.8 g N/m
2
 had 
higher NO
3
 levels at 12 and 16 WAP than other treatments, possibly because it is a 
controlled released fertilizer (CRF).  This indicates that while CRF may have lower N 
levels in soil water after initial application, it may continue to leach more N than other 
fertilizer sources over time. 
 
Water pH and EC.  There were no differences in soil solution pH among any treatment 
throughout the study (Table 1.6).  EC level of Peafowl fertilizer (9.8 g N/m
2
) was 
significantly higher than all other treatments at 2 WAP (Table 1.6).  At 4 WAP, Peafowl 
(9.8 g N/m
2
), and CPL at 19.6, 29.4, 39.2, and 49.0 g N/m
2
 had the highest EC levels.  By 
8 WAP Peafowl (9.8 g N/m
2
) and CPL (49.0 g N/m
2
) had the highest EC levels among 
any treatment, however CPL (49.0 g N/m
2
) was statistically similar to other treatments.  
At 12 WAP, CPL (39.2 g N/m
2
) had the highest EC level; however EC levels were 
similar to both rates of Peafowl fertilizer, Polyon at 9.8 g N/m
2
, and CPL at 19.6 and 49.0 
g N/m
2
.  At the conclusion of the study (16 WAP) there were minor differences in EC 
levels among treatments. 
 
Experiement 2 
Growth indices (GI) and Dry weights (DW).  Petunia GI at 4 WAP indicated that Peafowl 
fertilizer at both rates (4.9 and 9.8 g N/m
2
) along with CPL at rates of 19.6, 29.4, 39.2, 
 
77 
 
 
and 49.0 g N/m
2
 grew the largest plants, a trend that continued at 8 WAP (Table 2.1).  By 
12 WAP petunias were largest when fertilized with Peafowl (4.9 g N/m
2
) and CPL at 
rates of 19.6, 29.4, 39.2, and 49.0 g N/m
2
.  As in experiment 1, petunia DW indicated that 
plants fertilized with CPL were statistically similar to plants fertilized with inorganic 
fertilizers at the same rate. 
 At 4 WAP, Peafowl (9.8 g N/m
2
) along with CPL at rates of 19.6, 29.4, 39.2, and 
49.0 g N/m
2
 grew the largest verbena according to plant GI (Table 2.1).  By 12 WAP 
Polyon (9.8 g N/m
2
) along with all CPL treatments had the highest GI.  While verbena GI 
indicated that CPL grew plants equal to or smaller than the inorganic fertilizers in 
experiment 1, experiment 2 results show that CPL treatments out-performed Peafowl 
fertilizer when the same N rate was used.  Also, when verbena were fertilized with equal 
N rates of Polyon and CPL, CPL grew plants larger than or equal in size to those 
fertilized with Polyon.   However, plant DW indicated that the highest rates of CPL (29.4, 
39.2, and 49.0 g N/m
2
) grew plants statistically similar to, or smaller than inorganic 
(Peafowl and Polyon) fertilizer treatments.  This could be due to the higher N rates in 
CPL treatments causing plants to become ?leggy? and therefore rendering 12 WAP GI 
inaccurate in respect to true plant size.  Little visible differences were observed among 
verbena for any fertilized treatment at 12 WAP. 
 
Leaf chlorophyll content (LCC).  LCC of petunia was generally similar for petunia 
throughout the study, however small differences did occur (Table 2.2).  At 4 WAP, plants 
in Peafowl fertilizer at both rates along with CPL at 29.4 and 49.0 g N/m
2
 had slightly 
higher LCC than other treatments.  LCC was again very similar among most treatments at 
 
78 
 
 
8 WAP, however by 12 WAP CPL treatment (4.9 g N/m
2
) had a statistically higher LCC 
than all other treatments except for the highest rates of CPL (39.2 and 49.0 g N/m
2
). 
 Similarly to petunia, verbena LCC at 4 WAP showed little differences between 
treatments (Table 2.2).  However by 8 WAP Peafowl (9.8 g N/m
2
), Polyon (4.9 and 9.8 g 
N/m
2
) as well as CPL at 19.6 g N/m
2
 had slightly higher LCC.  By 12 WAP, verbena 
fertilized with Polyon (9.8 g N/m
2
) had significantly higher LCC than all other 
treatments. 
 
Tissue Nutrient Content.  In general, petunia N and P nutrient content was similar among 
all treatments, and no differences were observed in leaf K content (Table 2.3).  N, P, and 
K were within recommended ranges (Mills and Jones, 1996).  No treatment yielded 
leaves containing sufficient ranges of Ca or B, however all other nutrients were present in 
adequate amounts. 
 Similar to petunia tissue nutrient content, little difference was observed in verbena 
N levels and all were above sufficiency range (1.43 to 1.90, Mills and Jones, 1996) 
(Table 2.4).  The highest level of CPL (49.0 g N/m
2
) had higher leaf P content than all 
other treatments with the exception of CPL at 39.2 g/N m
2
, which was similar to other 
CPL treatments.  Verbena K content was above sufficient levels in all treatments.  All 
other required nutrients were present at equal to or above the sufficiency range, with the 
exception of Ca and B, which were slightly lower.  Only minor differences occurred in 
micronutrient content with the exception of Mn which decreased as the level of CPL 
increased. 
 
 
79 
 
 
N levels in soil-water as NO
3
 - N and NH
4
 ? N.  At 1 WAP, there were minor differences 
in NO
3
 levels in water, and all treatments were equal to or less than the non-fertilized 
control (Table 2.5).  NH
4
 levels were also similar among all treatments, and the only 
significant difference occurred among Polyon (4.9 g N/m
2
) and CPL (9.8 g N/m
2
) in 
which Polyon fertilized plots had significantly higher water NH
4
 levels than the CPL (9.8 
g N/m
2
) plots.  At 2 WAP however, Peafowl (4.9 g N/m
2
) had significantly higher NO
3
 
levels in water than any other treatment, similar to results in experiment 1. No differences 
were observed in water NH
4 
at 2 WAP.  At 4 WAP Peafowl (4.9 g N/m
2
) again had the 
highest levels of NO
3
 in soil water (14.9 ppm) and was the only treatment with NO
3
 
levels exceeding the recommended range (10 ppm, EPA, 1972).  While Peafowl (4.9 g 
N/m
2
) levels were high, levels were similar to Peafowl (9.8 g N/m
2
) and CPL (39.2 g 
N/m
2
).  Again, no differences were observed in NH
4
 at 4 WAP.  By 8 WAP all NO
3
 
levels were within acceptable ranges and all treatments had NO
3
 levels similar to the non-
fertilized control, a trend that continued at 12 WAP.  NH
4
 levels at 8 WAP indicated no 
difference among any treatment, however by 12 WAP CPL (29.4 g N/m
2
) again had very 
high NH
4 
levels exceeding recommended levels, however NH
4
 levels of CPL at 29.4 g 
N/m
2
 were similar to CPL at rates of 9.8, 19.6, and 29.4 g N/m
2
.     
 
Water pH and EC.  No differences were observed in water pH among any treatment until 
8 WAP when CPL (39.2 g N/m
2
) became only significantly higher than CPL at 4.9 g 
N/m
2
 and the non-fertilized control (Table 2.6).  At 12 WAP water pH was highest in 
CPL treatments 19.6, 39.2, and 49.0 g N/m
2
. 
 
80 
 
 
 Water EC levels were similar among most treatments at 1 WAP (Table 2.6).  The 
only difference observed in water EC levels was among CPL (19.6 g N/m
2
) and CPL 9.8, 
29.4, and 39.2 g N/m
2
.  At 2 WAP the only difference observed was that CPL (49.0 g 
N/m
2
) was significantly higher than both rates of Polyon, as well as CPL at 4.9 and 9.8 g 
N/m
2
.  By 8 WAP EC levels began to level off, and only CPL (39.2 g N/m
2
) and Polyon 
(9.8 g N/m
2
) were different.  At 12 WAP, and CPL (39.2 g N/m
2
) had slightly higher EC 
levels than all other treatments with the exception of Peafowl (4.9 g N/m
2
) and CPL (19.6 
g N/m
2
) which were statistically similar. 
 
Experiment 3 
Growth indices (GI) and Dry weights (DW).  At 4 WAP plant GI indicated that petunias 
fertilized with CPL at 29.4 g N/m
2
 were largest, however GIs were similar to petunias 
fertilized with Peafowl fertilizer (9.8 g N/m
2
), and CPL at 4.9, 39.2, and 49.0 g N/m
2
 
(Table 3.1)  At 8 WAP petunias were largest when grown in CPL at 29.4, 39.2, and 49.0 
g N/m
2
; however petunias were statistically similar to petunias fertilized with Peafowl 
(9.8 g N/m
2
), Polyon (4.9 g N/m
2
), and CPL at 4.9 g N/m
2
.  By 12 WAP petunias were 
largest when fertilized with CPL at a rate of 49.0 g N/m
2
; however petunias were equally 
as large when fertilized with Peafowl (9.8 g N/m
2
) and CPL at rates of 29.4 and 39.2 g 
N/m
2
.  As in experiments 1 and 2, petunias grew as well in CPL treatments compared 
with inorganic fertilizers when the same N rate was applied.  Dry weights tended to 
increase as N rate increased (Table 3.1).  The largest difference observed among petunia 
DW in fertilized plots was between CPL (49.0 g N/m
2
) and Peafowl (4.9 g N/m
2
).  In 
general, all other treatments had similar DW.  In addition, as in the previous two 
 
81 
 
 
experiments, petunia DW were statistically similar among plants fertilized with CPL and 
Peafowl or Polyon at the same N rate. 
 At 4 WAP dusty miller fertilized with Peafowl (9.8 g N/m
2
) were significantly 
larger than all other treatments (Table 3.1).  By 12 WAP dusty miller fertilized with 
Polyon (9.8 g N/m
2
) were larger than all other treatments with the exception of Peafowl 
(9.8 g N/m
2
) which were statistically similar.  As expected,  dusty miller DW fertilized 
with Polyon (9.8 g N/m
2
) were larger than all other treatments, however differences were 
not significant with the exception of CPL at 29.4 and 39.2 g N/m
2
) which had 
significantly less plant DW.  
 
Leaf chlorophyll content (LCC).  As in experiments 1 and 2, at 4 WAP petunias showed 
only minor differences in LCC.  At 8 WAP differences became more pronounced as 
Polyon (9.8 g N/m
2
) had significantly higher LCC than all other treatments.  This trend 
continued at 12 WAP, however by 12 WAP Polyon (4.9 g N/m
2
) and CPL (49.0 g N/m
2
) 
were statistically similar. 
 Dusty miller LCC were in general fairly similar among most treatments at 4 WAP 
and by 8 WAP no differences were observed.  At 12 WAP Polyon treatments at both 
rates grew dusty miller with the highest LCC, however LCC was similar to Peafowl 
brand (9.8 g N/m
2
), and CPL at rates of 4.9, 19.6, 39.2, and 49.0 g N/m
2
. 
 
Tissue Nutrient Content.  Petunias fertilized with Polyon (either rate) along with CPL 
(49.0 g N/m
2
) had higher foliar N content than other treatments (Table 3.3).  P content 
was highest in petunias fertilized with CPL at 39.2 and 49.0 g N/m
2
.  K was also highest 
 
82 
 
 
in petunias grown in CPL.  All other essential nutrients were within sufficiency ranges 
(Mills and Jones, 1996) with the exception of Ca and B which were slightly less. Mn 
decreased while Na tended to increase as the rate of CPL increased. 
 Dusty miller foliar N content was highest in Polyon (4.9 g N/m
2
), however N 
levels were similar to Polyon at 9.8 g N/m
2
, and CPL at 39.2 and 49.0 g N/m
2
 (Table 3.4). 
P content was highest in treatments fertilized with CPL, and P content tended to increase 
as the rate of CPL increased.  Again, all nutrients were present within the sufficiency 
ranges with the exception of Ca and B which were slightly less.  As in petunia, Mn 
tended to decrease as the rate of CPL increased. 
 
N levels in soil-water as NO
3
 - N and NH
4
 ? N.  At 1 WAP NO
3
 levels were similar and 
only Polyon (9.8 g N/m
2
) and CPL (29.4 g N/m
2
) were significantly different (Table 3.5).  
NH
4
 levels were highest in CPL (29.4 g N/m
2
) at 1 WAP, however no treatment was 
within EPA recommended levels.  At 2 WAP, NO
3
 levels were highest in CPL (29.4 g 
N/m
2
), however NO
3
 levels were similar in plots fertilized with CPL (39.2), Peafowl 
brand (9.8 g N/m
2
), and Polyon (4.9 g N/m
2
).  No differences were observed in water 
NH
4
 levels at 2 WAP.  At 4 WAP, again, CPL (29.4 g N/m
2
) had higher NO
3
 levels than 
all other treatments, and NH
4
 levels were similar among all treatments.  Similarly to 
experiment 2, by 8 WAP, no differences occurred in water NO
3
 and NH
4
, a trend that 
continued throughout the duration of experiment 3. 
 
Water pH and EC.  At 1 WAP, soil solution pH was highest in CPL (49.0 g N/m
2
), 
however pH levels of plots fertilized with Peafowl (4.9 g N/m
2
), Polyon (4.9 and 9.8 g 
 
83 
 
 
N/m
2
), as well as CPL (rates of 4.9, 9.8, 19.6, and 39.2 g N/m
2
) were similar (Table 3.6).  
At 2 WAP pH levels were generally similar among all treatments with the exception of 
Polyon (4.9 g N/m
2
) and the non-fertilized control which were significantly more alkaline 
than Peafowl brand (9.8 g N/m
2
).  At 4 WAP no differences were observed in water pH.  
Small differences occurred at 8 WAP, however by 12 WAP all treatments were 
statistically similar. 
 EC levels were similar at 1 WAP, and only CPL (29.4 g N/m
2
) had a significantly 
higher EC level than Peafowl (9.8 g N/m
2
), Polyon (9.8 g N/m
2
), CPL (4.9 g N/m
2
), and 
the non-fertilized control.  By 2 WAP EC levels began to increase as the rate of CPL 
increased and by 4 WAP CPL (49.0 g N/m
2
) had a significantly higher EC level than all 
other treatments with the exception of CPL at 39.2 g N/m
2
, which was statistically 
similar, a trend that continued at 8 WAP.  By 12 WAP, the two highest CPL rates still 
had the highest EC levels, but where now statistically similar to Peafowl brand (4.9 g 
N/m
2
), Polyon (9.8 g N/m
2
), and CPL treatments 9.8, 19.6, 29.4, and 39.2 g N/m
2
. 
 
Discussion 
 Similarities among treatments in these studies indicate that use of CPL as a 
fertilizer for landscape annual bedding plants could produce plants equal to or larger than 
plants fertilized with traditional commercially available inorganic fertilizers.  Final plant 
GI and DW in all three experiments indicate that petunias grew as large or larger when 
fertilized with CPL compared to an inorganic fertilizer at the same rate.  Verbena GI and 
DW in experiment 1 also demonstrate that verbena grew similarly when fertilized with 
equal rates of CPL compared to inorganic fertilizers, and in experiment 2, plants 
 
84 
 
 
fertilized with CPL grew better than when fertilized with inorganic fertilizers.  In 
experiment 3, dusty miller also grew as large in CPL treatments in comparison to 
inorganic fertilizer treatments.  Both petunia and verbena growth tended to increase in 
size as the rate of CPL increased.   
 Comparatively, a study by Altland (2002) evaluated the growth of ?Peppermint 
Cooler? vinca (Catharanthus roseus (L.) G. Don ?Peppermint Cooler?), ?Bonanza 
Yellow? marigold (Tagetes patula L. ?Bonanza Yellow?), and ?Hawaii Blue? ageratum 
(Ageratum houstonianum Mill. ?Hawaii Blue?) when fertilized with different fertilizer 
formulations, methods of application, and frequencies.  Fertilizer treatments were applied 
to landscape bedding plants in raised beds simulating an urban landscape.  Fertilizers 
evaluated included: Osmocote 14-14-14 and 17-7-12 controlled release fertilizers 
(CRF?s), 13-13-13 and 15-0-15 granular water-soluble (GWS), and industry practice 
treatment (IP) of incorporating a CRF preplant and topdressing a GWS fertilizer 
postplant, and an organically-based fertilizer (OBF) composed of recycled newspaper and 
raw chicken manure.  Results from this study indicate the organically based fertilizer 
resulted in larger, more attractive (higher foliar color ratings) plants than inorganic 
fertilizers.  Our study had similar results in that CPL treatments generally grew plants as 
large as or larger than the inorganic fertilizers; however in some cases the CPL treatment 
had a much higher N rate than the inorganic treatments. 
 There were few differences in LCC of petunia or verbena in experiment 1.  In 
experiment 1 at 12 WAP, petunias did have the highest LCC when fertilized with CPL 
(49.0 g N/m
2
), however LCC were similar to Peafowl (9.8 g N/m
2
), Polyon (4.9 g N/m
2
), 
and CPL at both 29.4 and 39.2 g N/m
2
.  In the same experiment, verbena LCC were 
 
85 
 
 
similar among all treatments at 12 WAP with the exception of the non-fertilized control, 
which had significantly less LCC than all other treatments except the lowest rate of CPL.  
At the conclusion of experiment 2, petunias had the highest LCC when fertilized with 
CPL at 4.9 g N/m
2
, while verbena had the highest LCC when fertilized with Polyon at the 
9.8 g N/m
2
 rate.  In experiment 3, petunias had the lower LCC when fertilized with CPL 
in comparison with the inorganic equivalent.  Dusty miller also had the highest LCC 
when fertilized with either rate of Polyon, however LCC were similar to Peafowl brand 
(9.8 g N/m
2
), and CPL at rates of 4.9, 19.6, 39.2, and 49.0 g N/m
2
.  While few differences 
did occur over the course of the three experiments, visual differences in foliar color were 
non-existent.   
 Tissue nutrient content also yielded very few differences among treatments, and 
all fertilized plants had sufficient levels of most required nutrients. 
 NO
3
 and NH
4
 levels in experiment 1 were extremely high in comparison with 
results from experiments 2 and 3, and levels remained high in most treatments until 8 
WAP.  This is possibly due to drought conditions for the initial portion of the study, 
which slowed N leaching.  In all three experiments, N leaching (NO
3
 and NH
4
) from CPL 
was less than or equal to N leaching compared to inorganic fertilizers at the same N rate.  
 A similar sequence of studies was conducted by Altland (2002) in which 
organically based fertilizers (OBF) (fresh cage layer poultry manure + recycled 
newspapers) were compared with commonly used inorganic fertilizer formulations.  
Altland reported that the OBF had higher total soil-water N (NO
3
 + NH
4
) in comparison 
with the inorganic formulations in the majority of experiments conducted.  However, 
Atland?s studies evaluated fresh poultry manure, while our experiments used fully 
 
86 
 
 
composted poultry litter. While composting litter prior to application will result in the 
loss of some nutrients, it may be beneficial in terms of reducing odor and non-point 
source pollution from N leaching. 
 In experiment 1, Peafowl (9.8 g N/m
2
) had the highest NH
4
 levels at 2, 4, and 8 
WAP and the highest NO
3
 levels at 4 and 8 WAP.   N leaching in experiment 1 from the 
inorganic fertilizers was similar to CPL N leaching, even when 5 times the fertilizer rate 
was applied using CPL.  In experiment 2, NO
3
 and NH
4
 leaching from CPL treatments 
was equal to or less than N leaching from inorganic treatments, with an exception of 
samples taken at 8 WAP, when CPL (39.2 g N/m
2
) NO
3
 water levels were significantly 
higher than either Peafowl or Polyon brand fertilizers; however a much higher N rate was 
applied via CPL.  At 12 WAP NH
4
 water levels were also higher in CPL treatments.  
Experiment 3 water samples indicate NH
4
 levels were also highest at 1 WAP in CPL 
(29.4 g N/m
2
), however no other differences occurred throughout the duration of the 
study.  NO
3
 levels were also highest in CPL (29.4 g N/m
2
) at 2 and 4 WAP, however by 8 
WAP no other differences in water NO
3
 levels occurred.   
 In experiment 1, NO
3
 and NH
4
 levels were consistently higher than recommended 
levels until 8 WAP.  While total N leaching was less in experiments 2 and 3, especially in 
earlier weeks, NO
3
 and NH
4
 levels exceeded recommended levels throughout the studies.  
A similar situation was reported by Timmons and Holt (1977) where mean annual flow-
weighted concentration of inorganic N (NH
4
 + NO
3
) in surface runoff from unfertilized 
native prairie was 1.3 mg/L, with a maximum value of 13.6 mg/L observed during a 5 
year study.  In addition, Sharpley et al., (1983) reported NH
4
 in runoff from unfertilized 
pasture (0.9 mg/L) and NO
3
 levels consistently higher than the critical values associated 
 
87 
 
 
with accelerated eutrophication (0.3 mg/L).  Consequently, Sharpley (et al., 1983) 
reported that it appears to be unrealistic to attempt to attain or maintain NH
4
 or NO
3
 
concentration in surface runoff from fertilized agricultural land, below the recommended 
levels.   
 The liming effects of poultry litter have been well documented (Hue, 1992; 
Kingery et al., 1993) and the EPA has set guidelines stating that soil solution pH levels 
should remain between 6.5 and 8.5.  If pH becomes acidic (below 6.5), drinking water 
can have a bitter metallic taste and corrosion of pipes and other plumbing can occur.  If 
pH rises above 8.5, the water can have a ?slippery? feel and can cause deposits in certain 
materials (EPA, 2009).  In our study, no differences occurred in soil solution pH levels in 
experiment 1, however pH was slightly more acidic at all dates than recommended (EPA, 
1972).  In experiment 2, all treatments had similar pH levels until 8 WAP, but only CPL 
(39.2 g N/m
2
) and CPL (4.9 g N/m
2
) were significantly higher.  By 12 WAP in 
experiment 2, the higher rates of CPL tended to have higher pH, which was expected.  
Soil solution pH remained within acceptable levels throughout the duration of experiment 
2. Differences did occur in water pH in experiment 3, however at the conclusion of the 
study no differences were observed, and CPL did not raise pH above acceptable levels 
(8.5) (EPA, 1972).   
 EC levels were highest in treatments having the highest NO
3
 and NH
4
 levels.  
Throughout all three experiments, only Peafowl (9.8 g N/m
2
) in experiment 1 at 2 WAP 
had an EC level of 4.9, which could be damaging to more sensitive crops; however, these 
levels dissipated quickly, and no negatives effects occurred in this experiment. 
 
88 
 
 
 In summary, results from these experiments demonstrate that CPL can be used 
successfully as a fertilizer for annual bedding plants.  In most cases, plants grew as well 
or better when equal rates of fertilizer were applied either using CPL or commercially 
available inorganic fertilizer formulations.  In respect to non-point source pollution, these 
experiments also indicate that composted poultry litter could be used at much higher rates 
of N than inorganic fertilizers resulting in plants with greater size while minimizing 
negative environmental impacts.  As fertilizer prices continue to rise, landscapers and 
homeowners will begin to look for alternatives to expensive inorganic fertilizer sources.  
CPL could provide nutritional requirements needed for healthy plant growth, and the use 
of CPL in the landscape will provide poultry producers an outlet for their poultry waste 
that is environmentally friendly.  While CPL and other organic fertilizer sources may 
never fully replace the need for inorganic fertilizers, CPL can supplement other fertilizer 
sources while minimizing negative environmental impacts. 
 
 
 
 
 
 
 
 
 
 
 
89 
 
 
Literature Cited 
Atland, J.E.  2002. Fertilization practices for landscape bedding plants.  Auburn 
 University, Auburn, AL. PhD. diss. 
 
Burmester, C.H., C.W. Wood, and C.C. Mitchell.  1991.  Broiler litter promising as 
 nitrogen source for cotton.  Highlights of Agr. Res. Auburn Univ. Summer 1991. 
 38(2):3. 
 
Environmental Protection Agency. 1972.  Water quality criteria. United States 
 Environmental Protection Agency, Washington, D.C. 
 
Environmental Protection Agency. 2009. Drinking Water Contaminants.  Accessed 
 June 4, 2009. http://www.epa.gov/ogwdw000/contaminants/index.html. 
 
Feagley, S.E., W.J. Grichar, and J.D. Nerada.  2005.  Use of chicken litter for 
 bermuda grass production in south Texas. J. of Sustainable Agriculture Vol. 25 
 (3) 2005. p. 67-90. 
 
Hairston, J.E. and L. Stribling. 1995. Getting to know water: Understanding water as 
 a resource. Alabama Cooperative Extension. Circular 790. 
 
Hue, N.V. 1992. Correcting soil acidity of a highly weathered ultisol with chicken 
 manure and sewage sludge. Commun. Soil Sci. Plant Anal. 23:241-264. 
 
90 
 
 
 
Kingery, W.L., C.W. Wood, D.P. Delaney, J.C. Williams, G.L.Mullins, and E. van 
 Santen. 1993. Implications of long-term land application of poultry litter on tall 
 fescue pastures. J. Prod. Agric. 6:315-395. 
 
Mills, H.A. and J.B. Jones.  1996. Plant analysis handbook II. MicroMacro 
 Publishing. Athens, Ga. 
 
Mitchell, C.C., J.O. Donald, and J. Martin.  1995. The value and use of poultry waste as 
 fertilizer. Alabama Cooperative Extension System. 3 July 2007. 
 http://hubcap.clemson.edu/blpprt/Aub-244.html. 
 
      Moore, Jr., P.A., T.C. Daniel, A.N. Sharpley and C.W. Wood. 1996. Poultry Manure   
 Management. p. 60-77. In: J.F. Power et. al (ed.) Agricultural uses of  
 Municipal, Animal, and Industrial Byproducts. U.S. Dept. of Agric.-ARS Rept. 
 No. 44. Natl. Technical Information Serv. Port Royal Rd, Springfield, VA. 
 
Porch, D.W., C.H. Gilliam, J.E. Brown, J.L. Adrian, and J.T. Eason.  1990.  Broiler 
 litter vs commercial fertilizer produces earlier, larger, tomatoes.  Highlights of 
 Agr. Res. Auburn Univ. Fall 1990.  37:5. 
 
 
91 
 
 
Reeder, J.A., C.H. Gilliam, C.C. Mitchell, and J.O. Donald.  1992.  Bedding plant 
 response to incorporated broiler litter.  Proc. Southern Nur. Assn. Res. Conf.  Vol. 
 37:298-299. 
 
Sharpley, A.N., J.K. Syers, and R.W. Tillman. 1983. Transport of ammonium and 
 nitrate nitrogen in surface runoff from pasture as influenced by urea application. J. 
 Water, Air, and Soil Pollution 20:425-430. 
 
Timmons, D.R. and R.F. Holt. 1977. Nutrient losses in surface runoff from a native 
 prarie. J. Environ. Qual. 6:369-373. 
 
United States Department of Agriculture.  2008.  Agricultural statistics for 2007.  
 U.S. Dept. Agr., Washington, D.C. 
 
Warren, S.L. and C.D. Safley.  1990.  Use of compost poultry litter in the horticulture 
 industry.  Proc. National Waste Management Symposium.  Auburn University 
 Printing Service, pp. 144-149, October, 1990. 
 
Wen-yuan, H.  2007.  Tight supply and strong demand may raise U.S. nitrogen 
 fertilizer prices.  Amber Waves  5(5):7. 
 
 
92 
 
 
Wolfe, K., and Humphries, G. 2007.  University of Georgia Center for Agribusiness 
 and Economic Development.  Landscape and nursery utilization of composted 
 manure.  UGA College of Agricultural and Environmental Sciences Report 07-09. 
 
 
 
 
 
 
 
Table 1.1 Effect of fertilizers on growth indices
Z 
and shoot dry weights
Y
 of 'Celebrity Red' petunia and 'Quartz Scarlet' verbena.
Treatment Rate                 'Celebrity Red' Petunia
(g N/m
2
)4 WAP
X
8 WAP 12 WAP Dry Wt. 4 WAP 8 WAP 12 WAP Dry Wt.
13-13-13 Peafowl? 4.9 13.5 bc
W
18.6 cd 26.1 cde 123.8 abc 17.1 ab 21.0 bc 22.9 cd 93.6 bc
13-13-13 Peafowl? 9.8 15.3 ab 22.2 ab 28.1 bcd 150.4 a 18.7 a 22.7 ab 25.4 abcd 113.2 ab
13-13-13 Polyon? 4.9 12.5 cd 16.8 d 24.5 de 92.1 bc 16.1 b 22.3 abc 26.0 ab 111.0 ab 
13-13-13 Polyon? 9.8 13.6 abc 20.8 bc 30.2 ab 127.3 ab 16.6 ab 23.1 ab 25.5 abc 109.7 ab
CPL
V
4.9 13.4 bc 20.6 bc 26.9 bcd 109.2 bc 15.6 b 22.6 ab 24.6 bcd 107.7 ab
CPL 9.8 14.2 abc 21.6 bc 27.8 bcd 121.9 abc 15.4 b 22.8 ab 24.4 bcd 94.0 bc
CPL 19.6 15.5 a 20.8 bc 28.9 bc 126.9 ab 16.1 b 23.2 ab 24.2 bcd 117.1 ab
CPL 29.4 14.4 ab 23.6 ab 30.4 ab 147.6 a 17.1 ab 22.9 ab 25.5 abc 112.5 ab
CPL 39.2 15.1 ab 25.0 a 33.2 a 150.2 a 17.7 ab 23.7 ab 27.6 a 122.5 ab
CPL 49 13.8 abc 22.9 ab 30.7 ab 156.5 a 16.3 b 24.1 a 26.2 ab 126.1 a
Non-fertilized control *** 11.3 d 16.0 d 22.8 e 90.1 c 15.7 b 19.8 c 22.7 d 78.6 c
Z
Growth indices = [(height + width1 + width2)/3]
Y
Dry weights measured in grams, taken from average dry weight of 5 plants per plot from each replication. 
X
WAP = Weeks after planting.
W
Means separated within columns using Duncan's Mutliple Range Test (alpha = 0.05). 
V
CPL = Composted poultry litter.
'Quartz Scarlet' Verbena
 
 
93
 
 
 
 
 
 
 
 
Table 1.2 Effect of fertilizers on leaf chlorophyll content
Z
 of 'Celebrity Red' petunia and 'Quartz Scarlet' verbena.
Rate
(g N/m
2
)4 WAP
Y
8 WAP 12 WAP 4 WAP 8 WAP 12 WAP
13-13-13 Peafowl? 4.9 48.8 a
X
49.0 abc 38.1 c 45.6 a 44.7 a 43.0 a
13-13-13 Peafowl? 9.8 48.4 a 48.9 abc 43.5 ab 49.0 a 44.4 a 42.9 a
13-13-13 Polyon? 4.9 46.9 a 48.2 abc 42.7 ab 46.6 a 46.0 a 45.2 a
13-13-13 Polyon? 9.8 48.9 a 49.5 ab 42.0 bc 47.8 a 46.4 a 42.5 a
CPL
W
4.9 46.5 a 44.4 C 40.4 bc 45.2 a 43.0ab 40.4 ab
CPL 9.8 49.2 a 46.9 bc 41.8 bc 45.1 a 41.5 ab 44.3 a
CPL 19.6 46.6 a 46.3 bc 40.5 bc 44.2 a 43.2 ab 42.4 a
CPL 29.4 48.0 a 46.2 bc 44.1 ab 45.0 a 45.3 a 43.3 a
CPL 39.2 47.9 a 47.5 abc 44.2 ab 47.5 a 45.8 a 42.0 a
CPL 49 49.8 a 51.9 a 46.7 a 46.4 a 47.2 a 44.7 a
Non-fertilized control *** 47.2 a 46.0 bc 41.9 bc 45.0 a 38.3 b 36.2 b
Z
Leaf chlorophyll content quantified using a SPAD-502 Chlorophyll Meter (Minolta Camera Co., Ramsey, NJ) 
(average of 5 leaves per plant).
Y
WAP = Weeks after planting.
X
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range
Test. (alpha = 0.05).
W
CPL = Composted poultry litter.
Quartz Scarlet' Verbena  'Celebrity Red' PetuniaTreatment
 
 
94
 
 
 
 
 
 
 
 
Table 1.3 Effect of fertilizer on tissue nutrient content of Petunia spp.  'Celebrity Red', Experiment 1.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Cd (ppm) Cr (ppm) Na (ppm) Ni (ppm) Pb (ppm) C (%)
13-13-13 Peafowl? 4.9
2.0 b
Y
0.25 d 4.8 a 0.85 ab 0.27 ab 24.8 ab 350.6 ab 110.4 ab 11.6 abc 88.0 ab 509.0 ab 2.4 b 1.3 b 637.8 e 2.0 ab 8.3 ab 40.3 d
13-13-13 Peafowl? 9.8 2.2 ab 0.27 cd 4.8 a 0.87 ab 0.28 ab 23.0 b 293.2 ab 118.0 a 9.8 c 92.0 ab 410.2 ab 0.14 b 0.0 b 813.4 de 0.66 b 5.4 b 40.6 bcd
13-13-13 Polyon? 4.9 2.1 ab 0.25 d 4.4 a 0.91 ab 0.28 ab 21.8 b 402.2 a 111.2 ab 17.2 ab 88.8 ab 592.0 a 0.34 b 0.10 b 565.4 e 0.34 b 6.6 b 40.5 cd
13-13-13 Polyon? 9.8 2.4 a 0.27 cd 4.7 a 0.91 ab 0.30 a 22.6 b 329.6 ab 104.0 abc 11.1 abc 85.4 ab 440.6 ab 0.16 b 0.12 b 680.8 e 0.48 b 12.0 ab 41.1 abcd
CPL
X
4.9 2.0 ab 0.26 d 4.4 a 0.87 ab 0.27 ab 22.0 b 410.2 a 110.0 ab 17.6 a 83.2 ab 621.2 a 0.20 b 0.0 b 785.0 de 1.1 b 12.4 ab 41.0 abcd
CPL 9.8 2.1 ab 0.26 d 4.2 a 0.88 ab 0.26 b 21.2 b 330.6 ab 93.0 bc 12.8 abc 80.4 ab 491.6 ab 0.22 b 0.0 b 1128.8 d 0.0 b 11.1 ab 41.4 abc
CPL 19.6 2.1 ab 0.29 bc 4.5 a 0.90 ab 0.27 ab 29.2 a 381.6 ab 102.0 abc 17.6 a 87.2 ab 566.2 ab 7.5 a 6.8 a 1617.8 c 6.1 a 15.8 a 41.4 abc
CPL 29.4 2.1 ab 0.30 ab 4.4 a 0.88 ab 0.26 b 21.8 b 296.4 ab 107.4 abc 11.8 abc 79.2 ab 422.8 ab 0.2 b 0.08 b 2007.8 bc 0.0 b 7.3 b 41.4 abc
CPL 39.2 2.1 ab 0.32 ab 4.7 a 0.88 ab 0.28 ab 22.2 b 251.8 b 97.6 abc 9.9 c 82.8 ab 371.2 b 0.18 b 0.34 b 2336.0 b 0.0 b 6.1 b 41.9 a
CPL 49 2.2 ab 0.33 a 4.8 a 0.79 b 0.26 b 21.4 b 371.2 ab 87.2 c 9.5 c 76.6 b 543.2 ab 0.24 b 0.0 b 2987.8 a 0.42 b 8.6 ab 41.5 ab
Non-fertilized control *** 2.0 ab 0.26 d 4.9 a 0.99 a 0.29 ab 22.5 b 418.0 a 108.5 ab 10.6 bc 96.0 a 600.8 a 0.25 b 0.10 b 657.5 e 0.70 b 9.4 ab 41.6 a
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A N/A N/A N/A N/A N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium, Ca = calcium, Mg = magnesium, B = boron, Fe = iron, 
Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Cd = cadmium, Cr = chromium, Na = sodium, Ni = nickle, Pb = lead, C = carbon.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
95
 
 
 
 
 
 
 
 
Table 1.4 Effect of fertilizer on tissue nutrient content of Verbena hybrida.  'Quartz Scarlet', Experiment 1.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Cd (ppm) Cr (ppm) Na (ppm) Ni (ppm) Pb (ppm) C (%)
13-13-13 Peafowl? 4.9 1.9 a 0.25 e 3.1 a 1.2 a 0.47 abc 28.2 b 330.8 b 290.0 a 12.3 ab 118.0 a 461.8 b 1.4 b 1.4 b 179.6 bcde 3.3 a 3.7 b 42.5 a
13-13-13 Peafowl? 9.8 2.0 a 0.25 de 2.6 c 1.2 a 0.47 abc 27.8 b 1760.2 a 261.4 a 9.5 ab 95.8 bcd 2042.8 a 0.0 b 2.2 ab 153.2 e 3.4 a 5.1 b 41.1 a
13-13-13 Polyon? 4.9 1.9 a 0.27 de 2.8 abc 1.1 a 0.48 ab 26.4 b 332.8 b 211.4 b 12.2 ab 94.6 bcd 496.2 b 0.0 b 0.0 b 155.6 de 2.6 a 0.5 b 42.3 a
13-13-13 Polyon? 9.8 2.0 a 0.27 de 2.9 abc 1.1 a 0.51 a 26.4 b 341.0 b 202.8 bc 12.1 ab 100.8 abc 480.0 b 0.0 b 0.3 b 197.6 abcd 2.3 a 1.6 b 43.4 a
CPL
X
4.9 1.9 a 0.29 cd 2.7 c 1.2 a 0.49 ab 27.4 b 282.2 b 182.6 bc 9.3 ab 96.0 bcd 432.2 b 0.0 b 0.1 b 151.0 e 1.9 a 4.4 b 43.3 a
CPL 9.8 1.9 a 0.30 cd 2.8 abc 1.1 a 0.50 a 27.6 b 295.2 b 186.6 bc 6.5 b 88.2 bcde 440.8 b 0.0 b 0.0 b 158.0 cde 2.3 a 0.6 b 42.4 a
CPL 19.6 1.9 a 0.34 bc 2.8 bc 1.1 a 0.48 ab 33.2 a 279.2 b 181.0 bc 14.0 a 99.0 abc 406.8 b 5.3 a 5.2 a 167.6 cde 6.3 a 10.7 a 43.2 a
CPL 29.4 1.9 a 0.32 c 2.9 abc 0.9 b 0.39 d 24.0 b 229.2 b 161.8 c 7.6 ab 75.0 ed 312.8 b 0.0 b 0.0 b 215.2 ab 1.3 a 0.7 b 42.3 a
CPL 39.2 1.9 a 0.37 ab 2.9 abc 1.1 ab 0.44 bcd 26.8 b 721.0 ab 164.0 c 8.7 ab 72.8 e 473.0 b 0.1 b 0.4 b 201.0 abc 1.9 a 1.8 b 43.3 a
CPL 49 2.0 a 0.40 a 3.0 ab 1.1 ab 0.42 cd 26.2 b 358.6 b 182.2 bc 11.0 ab 80.6 cde 528.4 b 0.0 b 0.7 b 232.8 a 1.9 a 2.5 b 43.0 a
Non-fertilized control *** 1.7 a 0.33 bc 2.7 c 1.2 a 0.51 a 26.4 b 436.6 b 255.4 a 13.8 a 105.8 ab 662.0 b 0.2 b 0.0 b 158.0 cde 3.1 a 0.7 b 42.6 a
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A N/A N/A N/A N/A N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium, Ca = calcium, Mg = magnesium, B = boron, Fe = iron,
 Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Cd = cadmium, Cr = chromium, Na = sodium, Ni = nickle, Pb = lead, C = carbon.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
96
 
 
 
 
 
 
 
 
 
 
Table 1.5 Effect of fertilizers on N in soil water, experiment 1.
Rate
(g N/m
2
) N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
13-13-13 Peafowl? 4.9 121.0 ab 27.1 a
Y
111.3 bcd 3.9 b 22.9 b 0.87 b 0.87 b 0.10 ab 0.27 b 0.17 a
13-13-13 Peafowl? 9.8 76.4 bcd 5.3 b 141.6 abc 44.7 a 87.1 a 11.3 a 1.73 b 0.17 a 0.50 b 0.10 a
13-13-13 Polyon? 4.9 62.5 d 4.0 b 74.9 cd 0.4 b 0.93 b 0.07 b 0.20 b 0.03 b 0.23 b 0.07 a
13-13-13 Polyon? 9.8 90.5 abcd 12.9 ab 95.3 bcd 0.9 b 8.9 b 0.10 b 3.27 a 0.17 a 2.4 a 0.10 a
CPL
X
4.9 103.2 abcd 3.0 b 54.9 d 0.4 b 0.80 b 0.17 b 0.83 b 0.03 b 0.20 b 0.17 a
CPL 9.8 73.8 cd 9.3 ab 102.6 bcd 0.7 b 6.0 b 0.13 b 0.30 b 0.0 b 0.13 b 0.10 a
CPL 19.6 118.2 abc 7.4 ab 194.4 a 2.8 b 2.9 b 0.17 b 0.63 b 0.03 b 1.0 ab 0.27 a
CPL 29.4 79.7 bcd 7.0 ab 104.8 bcd 1.1 b 3.7 b 0.10 b 0.97 b 0.07 ab 0.87 ab 0.13 a
CPL 39.2 128.6 a 5.5 b 129. 0 abcd 1.6 b 1.3 b 0.23 b 0.67 b 0.06 ab 0.37 b 0.13 a
CPL 49 114.1 abc 21.7 ab 165.6 ab 3.1 b 8.8 b 0.27 b 0.17 b 0.0 b 0.53 b 0.20 a
Non-fertilized control *** 68.8 d 0.9 b 77.0 cd 0.2 b 1.3 b 0.17 b 0.50 b 0.0 b 0.53 b 0.10 a
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
16 WAP12 WAPTreatment 2 WAP
Z
4 WAP 8 WAP
 
 
97
 
 
 
 
 
 
 
 
 
Table 1.6 Effect of fertilizers on pH and electrical conductivity of soil water, experiment 1.
Rate
(g N/m
2
) pH
EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m)
13-13-13 Peafowl? 4.9 5.4 a 1.3 b 5.7 a 1.3 abcd 5.7 a 0.6 b 6.1 a 0.29 abcd 6.0 a 0.25 ab
13-13-13 Peafowl? 9.8 5.5 a 4.9 a 5.8 a 1.7 ab 5.3 a 1.4 a 5.7 a 0.53 ab 5.6 a 0.33 a
13-13-13 Polyon? 4.9 5.5 a 0.8 b 5.9 a 0.6 d 6.0 a 0.2 b 6.1 a 0.20 bcd 5.7 a 0.16 ab
13-13-13 Polyon? 9.8 6.1 a 1.1 b 6.3 a 0.9 bcd 6.1 a 0.3 b 6.0 a 0.28 abcd 5.9 a 0.25 ab
CPL
X
4.9 6.2 a 1.2 b 6.3 a 0.8 dc 6.1 a 0.3 b 6.2 a 0.21 bcd 5.9 a 0.16 ab
CPL 9.8 6.2 a 1.1 b 6.0 a 1.0 bcd 5.8 a 0.3 b 5.9 a 0.26 bcd 5.8 a 0.18 ab
CPL 19.6 5.7 a 1.8 b 6.1 a 2.0 a 5.9 a 0.7 b 6.2 a 0.30 abcd 5.9 a 0.29 ab
CPL 29.4 5.2 a 1.7 b 5.7 a 1.2 abcd 5.9 a 0.4 b 6.0 a 0.27 bcd 6.2 a 0.20 ab
CPL 39.2 5.9 a 2.2 b 5.6 a 1.5 abc 6.0 a 0.7 b 5.7 a 0.60 a 6.0 a 0.25 ab
CPL 49 5.4 a 1.7 b 5.6 a 1.9 a 6.1 a 0.8 ab 6.2 a 0.49 abc 6.2 a 0.28 ab
Non-fertilized control *** 5.7 a 0.8 b 6.1 a 0.6 dc 6.3 a 0.2 b 6.2 a 0.16 d 6.2 a 0.13 b
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
Treatment 2 WAP
Z
4 WAP 8 WAP 12 WAP 16 WAP
 
 
98
 
 
 
 
 
 
 
 
Table 2.1 Effect of fertilizers on growth indices
Z 
and shoot dry weights
Y
 of 'Celebrity Red' petunia and 'Quartz Scarlet' verbena.
Treatment Rate
(g N/m
2
)4 WAP
X
8 WAP 12 WAP Dry Wt. 4 WAP 8 WAP 12 WAP Dry Wt.
13-13-13 Peafowl? 4.9 24.7 a 38.3 a 40.2 abcd 231.7 ab 14.2 cd 27.1 ab 26.4 c 189.4 abc
13-13-13 Peafowl? 9.8 25.2 a 38.8 a 39.2 bcd 252.8 a 17.0 a 26.9 abc 26.2 c 187.5 abc
13-13-13 Polyon? 4.9 19.2 cd 32.7 b 38.2 d 221.0 ab 12.7 e 26.2 abc 27.0 bc 191.7 abc
13-13-13 Polyon? 9.8 17.8 d 33.3 b 39.1 bcd 233.5 ab 13.4 de 26.7 abc 28.8 ab 233.8 a
CPL
V
4.9 19.5 c 32.2 b 38.2 d 215.6 ab 14.2 cd 28.1 a 29.7 a 224.9 ab
CPL 9.8 21.4 b 33.6 b 38.5 cd 226.7 ab 15.2 bc 27.3 ab 29.3 a 207.7 abc
CPL 19.6 24.0 a 38.8 b 41.3 abc 232.2 ab 16.2 ab 27.7 a 29.0 ab 200.7 abc
CPL 29.4 24.4 a 39.0 a 41.6 ab 263.2 a 16.3 ab 26.7 abc 27.8 abc 180.2 bc
CPL 39.2 25.5 a 40.9 a 42.7 a 274.0 a 16.11 ab 25.3 bc 28.7 ab 170.9 c
CPL 49 25.0 a 41.0 a 42.4 a 262.5 a 17.0 a 26.3 abc 30.1 a 176.6 bc
Non-fertilized control *** 18.2 cd 34.5 b 34.8 e 177.9 b 12.6 e 24.7 c 24.0 d 164.9 c
Z
Growth indices = [(height + width1 + width2)/3]
Y
Dry weights measured in grams, taken from average dry weight of 5 plants per plot from each replication. 
X
WAP = Weeks after planting.
W
Means separated within columns using Duncan's Mutliple Range Test (alpha = 0.05). 
V
CPL = Composted poultry litter.
'Quartz Scarlet' Verbena                'Celebrity Red' Petunia
 
 
99
 
 
 
 
 
 
 
Table 2.2 Effect of fertilizers on leaf chlorophyll content
Z
 of 'Celebrity Red' petunia and 'Quartz Scarlet' verbena.
Rate
(g N/m
2
)4 WAP
Y
8 WAP 12 WAP 4 WAP 8 WAP 12 WAP
13-13-13 Peafowl? 4.9 46.0 ab 36.3 bc 32.5 b 53.1 abc 47.5 b 36.2 bcd
13-13-13 Peafowl? 9.8 47.3 a 36.8 abc 32.7 b 53.4 ab 48.7 ab 37.4 bcd
13-13-13 Polyon? 4.9 43.3 bcd 38.7 ab 35.8 b 50.9 abc 48.7 ab 37.4 bcd
13-13-13 Polyon? 9.8 43.7 bc 39.1 a 36.3 b 50.4 bc 51.5 a 45.6 a
CPL
W
4.9 43.2 bcd 39.1 a 51.0 a 51.4 abc 48.4 b 40.1 b
CPL 9.8 42.4 cd 36.9 abc 35.5 b 52.2 abc 46.1 b 38.3 bcd
CPL 19.6 42.6 cd 37.0 abc 33.5 b 49.8 c 49.2 ab 34.4 cd
CPL 29.4 45.4 abc 37.7 abc 36.4 b 51.5 abc 48.3 b 37.4 bcd
CPL 39.2 44.1 bc 36.0 c 37.8 ab 54.3 a 48.2 b 36.2 bcd
CPL 49 44.8 abc 37.1 abc 38.1 ab 53.4 ab 47.5 b 38.5 bc
Non-fertilized control *** 40.5 d 35.4 c 31.0 b 42.9 d 47.6 b 33.7 d
Z
Leaf chlorophyll content quantified using a SPAD-502 Chlorophyll Meter (Minolta Camera Co., Ramsey, NJ) 
(average of 5 leaves per plant).
Y
WAP = Weeks after planting.
X
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range
Test. (alpha = 0.05).
W
CPL = Composted poultry litter.
Treatment   'Celebrity Red' Petunia Quartz Scarlet' Verbena
 
 
100
 
 
 
 
 
 
 
Table 2.3 Effect of fertilizer on tissue nutrient content of Petunia spp.' Celebrity Red', experiment 2.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Na (ppm)
13-13-13 Peafowl? 4.9 2.1 b 0.29 ab 2.0 a 0.80 ab 0.21 ab 29.8 bc 501.6 ab 110.2 a 20.4 bc 137.5 a 533.8 a 996.1 de
13-13-13 Peafowl? 9.8 2.0 b 0.27 b 2.0 a 0.73 b 0.20 ab 29.0 bc 317.1 ab 112.3 a 24.1 abc 142.2 a 258.8 a 1257.3 de
13-13-13 Polyon? 4.9 2.4 ab 0.28 ab 2.0 a 0.80 ab 0.22 a 31.9 ab 320.5 ab 94.7 a 23.7 abc 130.0 a 288.6 a 1269.3 de
13-13-13 Polyon? 9.8 2.4 a 0.28 ab 2.0 a 0.78 ab 0.21 ab 33.3 ab 517.8 ab 105.4 a 26.3 abc 119.8 a 499.0 a 1012.7 de
CPL
X
4.9 2.3 ab 0.31 ab 2.1 a 0.87 a 0.22 a 32.1 ab 348.8 ab 116.9 a 18.9 bc 131.5 a 325.4 a 1277.9 de
CPL 9.8 2.0 b 0.32 ab 2.1 a 0.82 ab 0.20 ab 28.9 bc 373.6 ab 114.8 a 22.5 bc 136.4 a 351.7 a 1530.4 cd
CPL 19.6 2.2 ab 0.33 ab 2.1 a 0.85 ab 0.20 ab 30.1 abc 689.3 a 125.0 a 35.4 a 121.0 a 580.4 a 1846.7 bc
CPL 29.4 2.3 ab 0.28 ab 2.0 a 0.76 ab 0.20 ab 34.3 a 479.5 ab 91.1 a 31.1 ab 116.0 a 480.3 a 1961.8 bc
CPL 39.2 2.3 ab 0.34 a 2.1 a 0.80 ab 0.20 ab 33.4 ab 269.6 b 99.8 a 17.8 c 130.6 a 237.0 a 2107.6 b
CPL 49 2.1 ab 0.31 ab 2.0 a 0.74 b 0.19 b 29.3 bc 480.3 ab 99.8 a 29.5 abc 124.9 a 450.1 a 2615.8 a
Non-fertilized control *** 2.3 ab 0.27 b 2.0 a 0.77 ab 0.20 ab 26.8 c 338.9 ab 91.8 a 22.8 bc 138.0 a 327.3 a 859.1 e
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium, 
Ca = calcium, Mg = magnesium, B = boron, Fe = iron, Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Na = sodium.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
101
 
 
 
 
 
 
 
Table 2.4 Effect of fertilizer on tissue nutrient content of Verbena hybrida.  'Quartz Scarlet', experiment 2.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Na (ppm)
13-13-13 Peafowl? 4.9 2.2 abc 0.25 d 1.6 d 1.2 ab 0.27 b 18.5 c 395.5 a 242.2 a 24.4 a 174.1 ab 410.6 a 198.6 a
13-13-13 Peafowl? 9.8 2.3 abc 0.25 d 1.6 bcd 1.0 b 0.28 ab 21.2 abc 950.3 a 235.2 a 18.1 a 167.4 ab 638.0 a 189.1 a
13-13-13 Polyon? 4.9 2.3 abc 0.26 d 1.6 abcd 1.2 ab 0.28 ab 20.2 abc 278.2 a 235.5 a 20.0 a 172.5 ab 244.9 a 185.2 a
13-13-13 Polyon? 9.8 2.5 a 0.27 d 1.7 ab 1.1 ab 0.27 ab 18.6 c 416.3 a 243.1 a 20.0 a 167.4 ab 228.5 a 166.7 a
CPL
X
4.9 2.4 ab 0.33 cd 1.7 a 1.2 a 0.29 a 20.4 abc 258.1 a 245.7 a 20.0 a 190.0 a 224.8 a 179.5 a
CPL 9.8 2.2 abc 0.40 bc 1.7 abc 1.3 a 0.28 ab 24.0 a 459.6 a 209.4 abc 25.8 a 163.9 ab 323.6 a 169.8 a
CPL 19.6 2.0 c 0.41 bc 1.6 abcd 1.3 a 0.28 ab 21.6 abc 416.3 a 224.0 ab 23.0 a 167.4 ab 371.7 a 169.5 a
CPL 29.4 2.1 bc 0.42 b 1.6 cd 1.2 ab 0.28 ab 19.8 bc 510.7 a 166.3 c 23.1 a 157.2 ab 485.7 a 172.7 a
CPL 39.2 2.0 bc 0.48 ab 1.7 abcd 1.2 ab 0.29 ab 22.9 ab 314.7 a 186.9 bc 20.5 a 157.2 ab 292.3 a 188.1 a
CPL 49 2.3 abc 0.51 a 1.7 abcd 1.2 ab 0.29 ab 23.5 ab 411.9 a 169.1 c 18.0 a 145.5 b 393.3 a 191.4 a
Non-fertilized control *** 2.2 abc 0.33 cd 1.7 abcd 1.3 a 0.29 a 23.4 ab 255.3 a 251.1 a 25.6 a 173.7 ab 228.9 a 175.5 a
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium,  
Ca = calcium, Mg = magnesium, B = boron, Fe = iron, Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Na = sodium.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
102
 
 
 
 
 
 
 
Table 2.5 Effect of fertilizers on N in soil water, experiment 2.
Rate
(g N/m
2
) N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
13-13-13 Peafowl? 4.9 2.7 ab 1.3 ab 12.5 a 3.2 a 14.9 a 1.3 a 1.0 b 1.1 a 1.0 a 1.6 b
13-13-13 Peafowl? 9.8 1.4 ab 0.97 ab 4.7 b 4.1 a 8.4 ab 2.9 a 0.33 b 0.57 a 1.1 a 0.0 b
13-13-13 Polyon? 4.9 0.80 ab 1.6 a 0.43 b 0.90 a 0.43 b 1.4 a 1.2 b 1.0 a 1.1 a 1.3 b
13-13-13 Polyon? 9.8 1.4 ab 1.1 ab 0.40 b 0.53 a 0.50 b 0.70 a 0.43 b 0.67 a 0.87 a 0.40 b
CPL
X
4.9 1.7 ab 0.83 ab 0.63 b 0.47 a 0.53 b 0.67 a 1.4 ab 1.3 a 0.73 a 0.67 b
CPL 9.8 0.10 b 0.30 b 0.53 b 0.83 a 0.43 b 1.0 a 1.5 ab 0.47 a 1.4 a 2.3 ab
CPL 19.6 3.5 a 0.87 ab 0.87 b 0.83 a 0.73 b 1.8 a 1.8 ab 1.7 a 2.8 a 2.7 ab
CPL 29.4 0.67 ab 0.93 ab 6.3 b 1.0 a 0.70 b 1.2 a 1.0 b 2.0 a 3.3 a 2.1 ab
CPL 39.2 0.97 ab 1.4 ab 5.3 b 2.4 a 3.1 ab 3.6 a 6.4 a 1.1 a 0.83 a 10.3 a
CPL 49 2.0 ab 1.2 ab 8.0 b 1.9 a 0.90 b 1.8 a 2.2 ab 0.47 a 0.90 a 0.13 b
Non-fertilized control *** 2.4 ab 0.80 ab 0.53 b 0.83 a 0.43 b 1.2 a 3.4 ab 0.77 a 0.57 a 0.83 b
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
2 WAP 4 WAP 8 WAP 12 WAPTreatment 1 WAP
Z
 
 
103
 
 
 
 
 
 
 
 
Table 2.6 Effect of fertilizers on pH and electrical conductivity of soil water, experiment 2.
Rate
(g N/m
2
) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m)
13-13-13 Peafowl? 4.9 6.6 a 0.23 ab 6.5 a 0.63 ab 7.2 a 0.52 abc 7.3 ab 0.31 ab 6.9 bc 0.39 ab
13-13-13 Peafowl? 9.8 6.8 a 0.25 ab 6.5 a 0.60 ab 6.9 a 0.60 ab 7.3 ab 0.30 ab 6.8 c 0.32 b
13-13-13 Polyon? 4.9 6.9 a 0.23 ab 7.2 a 0.31 b 7.3 a 0.28 bc 7.4 ab 0.22 ab 7.0 bc 0.31 b
13-13-13 Polyon? 9.8 7.2 a 0.25 ab 7.2 a 0.26 b 6.9 a 0.25 c 7.4 ab 0.20 b 6.8 c 0.27 b
CPL
X
4.9 6.8 a 0.22 ab 7.2 a 0.29 b 7.2 a 0.25 c 7.2 b 0.24 ab 6.9 bc 0.30 b
CPL 9.8 6.6 a 0.18 b 7.2 a 0.34 b 7.3 a 0.31 abc 7.6 ab 0.26 ab 6.8 c 0.36 b
CPL 19.6 6.5 a 0.30 a 7.2 a 0.43 ab 7.2 a 0.37 abc 7.6 ab 0.30 ab 7.2 ab 0.39 ab
CPL 29.4 6.5 a 0.18 b 6.6 a 0.45 ab 7.3 a 0.32 abc 7.4 ab 0.28 ab 6.8 c 0.37 b
CPL 39.2 6.7 a 0.21 b 6.7 a 0.56 ab 7.2 a 0.62  a 8.0 a 0.42 a 7.4 a 0.52 a
CPL 49 6.7 a 0.22 ab 6.4 a 0.78 a 7.3 a 0.47 abc 7.8 ab 0.33 ab 7.1 abc 0.30 b
Non-fertilized control *** 6.8 a 0.23 ab 7.3 a 0.30 b 7.2 a 0.29 bc 7.2 b 0.28 ab 6.8 c 0.31 b
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
8 WAP 12 WAP2 WAP 4 WAPTreatment 1 WAP
Z
 
 
104
 
 
 
 
 
 
 
 
Table 3.1 Effect of fertilizers on growth indices
Z 
and shoot dry weights
Y
 of 'Celebrity Red' petunia and Dusty Miller.
Treatment Rate                 'Celebrity Red' Petunia
(g N/m
2
)4 WAP
X
8 WAP 12 WAP Dry Wt. 4 WAP 8 WAP 12 WAP Dry Wt.
13-13-13 Peafowl? 4.9 17.1 bcd 23.3 d 25.3 bcde 56.7 c 16.3 bc 23.1 bcd 23.6 ed 144.4 abc
13-13-13 Peafowl? 9.8 18.2 abc 27.6 abc 26.5 abcd 87.2 abc 18.4 a 25.5 ab 27.5 ab 193.2 ab
13-13-13 Polyon? 4.9 16.5 cd 26.2 abcd 22.8 ef 78.3 abc 16.6 bc 24.6 bc 26.5 bc 181.4 abc
13-13-13 Polyon? 9.8 16.6 cd 25.2 cd 24.6 bcdef 86.4 abc 16.5 bc 27.6 a 29.5 a 223.2 a
CPL
V
4.9 17.8 abc 26.9 abc 24.8 bcdef 79.6 abc 15.8 c 25.2 abc 26.7 bc 181.5 abc
CPL 9.8 16.5 cd 24.8 cd 24.3 cdef 71.5 bc 16.4 bc 23.1 bcd 24.6 cd 175.7 abc
CPL 19.6 16.9 cd 25.5 bcd 23.6 def 76.9 abc 16.6 bc 22.5 cd 23.3 de 140.2 abc
CPL 29.4 19.1 a 28.9 a 28.0 ab 122.8 a 16.5 bc 21.2 de 22.6 de 125.6 bc
CPL 39.2 18.4 abc 28.5 a 27.7 abc 107.5 ab 15.8 c 23.1 bcd 25.0 bcd 131. 4 bc
CPL 49 19.0 ab 28.9 a 29.5 a 126.3 a 16.4 bc 23.5 bcd 24.7 cd 156.1 abc
Non-fertilized control *** 15.8 d 23.2 d 21.6 f 47.9 c 13.9 d 19.8 e 21.4 e 102.4 c
Z
Growth indices = [(height + width1 + width2)/3]
Y
Dry weights measured in grams, taken from average dry weight of 5 plants per plot from each replication. 
X
WAP = Weeks after planting.
W
Means separated within columns using Duncan's Mutliple Range Test (alpha = 0.05). 
V
CPL = Composted poultry litter.
Dusty Miller
 
 
105
 
 
 
 
 
 
 
Table 3.2 Effect of fertilizers on leaf chlorophyll content
Z
 of 'Celebrity Red' petunia and Dusty Miller.
Rate
(g N/m
2
)4 WAP
Y
8 WAP 12 WAP 4 WAP 8 WAP 12 WAP
13-13-13 Peafowl? 4.9 43.6 bc 39.8 c 36.4 f 66.1 ab 62.0 a 53.5 cd
13-13-13 Peafowl? 9.8 47.1 ab 40.4 bc 37.1 ef 67.7 ab 63.6 a 57.1 abc
13-13-13 Polyon? 4.9 45.3 abc 42.6 b 43.3 abc 65.9 ab 63.7 a 59.4 a
13-13-13 Polyon? 9.8 44.3 abc 45.0 a 46.5 a 69.3 a 64.1 a 59.1 a
CPL
W
4.9 44.5 abc 40.6 bc 38.2 def 66.3 ab 64.0 a 56.3 abc
CPL 9.8 42.3 c 40.3 bc 40.6 bcde 65.0 bc 60.4 a 54.3 bcd
CPL 19.6 43.8 bc 40.9 bc 39.3 def 64.5 bc 60.4 a 56.1 abc
CPL 29.4 47.4 ab 41.2 bc 40.2 cde 65.9 ab 60.6 a 54.4 bcd
CPL 39.2 43.0 c 40.9 bc 41.0 bcd 66.4 ab 62.0 a 55.5 abcd
CPL 49 48.2 a 40.2 bc 43.9 ab 65.9 ab 63.4 a 58.3 ab
Non-fertilized control *** 42.2 c 40.1 bc 33.1 g 61.4 c 62.0 a 51.5 d
Z
Leaf chlorophyll content quantified using a SPAD-502 Chlorophyll Meter (Minolta Camera Co., Ramsey, NJ) 
(average of 5 leaves per plant).
Y
WAP = Weeks after planting.
X
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range
Test. (alpha = 0.05).
W
CPL = Composted poultry litter.
Treatment   'Celebrity Red' Petunia Dusty Miller
 
 
106
 
 
 
 
 
 
 
Table 3.3 Effect of fertilizer on tissue nutrient content of Petunia spp.' Celebrity Red', experiment 3.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Na (ppm)
13-13-13 Peafowl? 4.9 2.1 c 0.33 fg 2.7 e 1.1 abc 0.52 c 25.0 b 544.8 a 142.8 ab 19.6 bc 110.2 a 507.8 ab 1869.2 f
13-13-13 Peafowl? 9.8 2.0 c 0.38 e 2.8 de 1.0 bcd 0.53 c 22.8 bc 352.8 a 149.6 a 16.6 bc 105.2 a 360.6 b 2113.6 ef
13-13-13 Polyon? 4.9 2.5 ab 0.36 ef 2.9 cde 1.2 ab 0.61 ab 25.6 b 409.2 a 126.6 bc 24.2 abc 104.2 a 381.6 b 2677.6 de
13-13-13 Polyon? 9.8 2.7 a 0.47 c 2.9 de 1.1 ab 0.61 ab 20.4 cd 385.6 a 147.0 ab 19.0 bc 95.0 ab 297.2 b 2812.8 de
CPL
X
4.9 2.1 c 0.36 ef 3.1 bcd 1.0 bcd 0.56 bc 26.0 b 420.4 a 95.6 def 16.4 c 82.6 bc 333.0 b 2273.2 ef
CPL 9.8 2.2 c 0.43 d 3.2 abc 1.1 ab 0.57 abc 24.2 bc 470.2 a 100.0 de 22.0 abc 88.2 b 458.8 ab 2459.0 ef
CPL 19.6 2.3 c 0.53 b 3.3 ab 1.0 bcd 0.57 abc 20.4 cd 461.8 a 83.2 efg 35.2 a 82.0 bc 419.6 ab 3303.6 cd
CPL 29.4 2.2 c 0.54 b 3.4 a 0.86 cde 0.54 c 18.0 d 538.8 a 75.4 fgh 29.6 abc 72.2 cd 512.8 ab 3835.0 bc
CPL 39.2 2.3 bc 0.55 ab 3.4 a 0.85 de 0.56 bc 18.2 d 377.8 a 70.0 gh 23.2 abc 71.6 cd 272.4 b 4270.0 ab
CPL 49 2.6 a 0.58 a 3.4 a 0.72 e 0.55 c 17.8 d 313.3 a 58.8 h 30.3 ab 67.0 d 227.8 b 4781.0 a
Non-fertilized control *** 2.2 c 0.31 g 3.0 cde 1.2 a 0.62 a 30.6 a 742.0 a 112.8 cd 25.4 abc 108.6 a 898.0 a 2320.4 ef
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium, 
Ca = calcium, Mg = magnesium, B = boron, Fe = iron, Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Na = sodium.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
107
 
 
 
 
 
 
 
 
 
Table 3.4 Effect of fertilizer on tissue nutrient content of Senecio cineraria (Dusty Miller), experiment 3.
Rate
Treatment
(g N/m
2
)
N (%) P (%) K (%) Ca (%) Mg (%) B (ppm) Fe (ppm) Mn (ppm) Cu (ppm) Zn (ppm) Al (ppm) Na (ppm)
13-13-13 Peafowl? 4.9 1.3 c 0.21 c 1.7 cde 0.91 ab 0.47 ab 29.3 bc 182.8 a 260.0 a 17.0 b 75.0 a 131.3 ab 2368.5 cd
13-13-13 Peafowl? 9.8 1.3 c 0.22 c 1.7 bcde 0.79 bcd 0.42 c 29.0 bc 132.6 a 241.0 ab 22.4 b 71.6 a 88.8 b 2020.0 d
13-13-13 Polyon? 4.9 1.6 a 0.21 c 1.7 bcde 0.89 abc 0.51 ab 28.4 c 139.8 a 183.8 cd 14.2 b 77.4 a 91.0 b 2774.2 abc
13-13-13 Polyon? 9.8 1.6 ab 0.21 c 1.6 e 0.79 cd 0.46 bc 26.6 c 145.8 a 203.4 bc 41.2 a 78.8 a 101.6 ab 2608.0 bc
CPL
X
4.9 1.4 c 0.24 c 1.8 abcd 0.87 abc 0.49 ab 34.2 a 137.4 a 181.0 cd 17.6 b 66.2 ab 93.6 b 2768.0 abc
CPL 9.8 1.4 bc 0.28 b 1.8 abc 0.87 abc 0.49 ab 36.0 a 149.0 a 165.0 cde 26.4 ab 73.0 a 111.4 ab 2599.0 bc
CPL 19.6 1.4 c 0.30 ab 1.9 a 0.89 abc 0.51 a 33.5 a 147.8 a 156.5 cde 29.5 ab 64.3 ab 112.8 ab 2819.3 ab
CPL 29.4 1.3 c 0.30 ab 1.8 bcde 0.82 abcd 0.47 ab 29.0 bc 134.8 a 141.6 def 19.8 b 57.8 ab 109.2 ab 2642.0 bc
CPL 39.2 1.4 abc 0.31 ab 1.8 abcd 0.75 de 0.48 ab 27.2 c 173.2 a 113.6 ef 30.4 ab 61.8 ab 142.6 a 2834.8 ab
CPL 49 1.5 abc 0.33 a 1.9 ab 0.68 e 0.47 ab 25.0 c 137.8 a 93.4 f 31.4 ab 48.0 b 100.0 ab 3141.8 a
Non-fertilized control *** 1.3 c 0.21 c 1.6 de 0.94 a 0.49 ab 33.0 ab 173.0 a 172.6 cd 21.2 b 76.6 a 135.4 ab 2724.2 abc
Sufficiency range
V
1.43 - 1.90 0.10 - 0.13 0.40 - 0.52 2.0 - 2.9 0.13 - 0.15 55 - 126 58 - 69 15 - 35 4 - 6 7 - 10
N/A
U
N/A
Z
Tissue analysis performed on 20 terminal shoots (5.1 cm - 7.6 cm or 2-3 in of most recently mature leaves) per plant; N = nitrogen, P = phosphorus, K = potassium, 
Ca = calcium, Mg = magnesium, B = boron, Fe = iron, Mn = manganese, Cu = copper, Zn = zinc, Al = aluminum, Na = sodium.
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
V
Sufficiency range published by Mills and Jones (1996).
U
N/A = Not applicable.
Tissue Nutrient Content
Z
 
 
108
 
 
 
 
 
 
 
 
Table 3.5 Effect of fertilizers on N in soil water, experiment 3.
Rate
(g N/m
2
) N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
N0
3
NH
4
13-13-13 Peafowl? 4.9 2.1 ab 0.87 c 0.70 b 4.6 a 1.6 c 5.4 a 4.4 a 0.33 a 2.0 a 0.93 a
13-13-13 Peafowl? 9.8 2.2 ab 3.6 b 5.3 ab 9.3 a 5.9 b 0.60 a 3.6 a 1.4 a 1.0 a 0.57 a
13-13-13 Polyon? 4.9 7.3 a 1.9 bc 6.5 ab 6.9 a 4.4 bc 6.2 a 4.2 a 1.7 a 2.6 a 1.3 a
13-13-13 Polyon? 9.8 1.5 ab 2.0 bc 1.3 b 3.4 a 3.6 bc 2.5 a 3.7 a 0.20 a 1.6 a 0.67 a
CPL
X
4.9 1.4 ab 2.0 bc 0.93 b 2.9 a 2.5 c 1.5 a 3.0 a 0.03 a 0.93 a 0.37 a
CPL 9.8 3.3 ab 2.0 bc 2.3 b 3.7 a 1.9 c 5.6 a 2.1 a 3.3 a 2.2 a 1.7 a
CPL 19.6 4.2 ab 1.8 bc 1.1 b 8.3 a 3.4 bc 7.1 a 5.9 a 0.73 a 2.4 a 2.2 a
CPL 29.4 0.43 b 15.7 a 9.6 a 2.9 a 9.1 a 0.37 a 5.1 a 0.77 a 3.1 a 2.3 a
CPL 39.2 7.0 ab 4.0 b 4.0 ab 8.1 a 3.9 bc 5.7 a 3.9 a 3.7 a 2.6 a 2.2 a
CPL 49 2.8 ab 1.7 bc 2.0 b 6.2 a 2.4 c 5.5 a 3.3 a 1.3 a 2.8 a 0.37 a
Non-fertilized control *** 1.0 ab 2.2 bc 0.73 b 3.8 a 1.1 c 3.4 a 2.2 a 1.3 a 1.1 a 0.83 a
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
8 WAP 12 WAPTreatment 1 WAP
Z
2 WAP 4 WAP
 
 
109
 
 
 
 
 
Table 3.6 Effect of fertilizers on pH and electrical conductivity of soil water, experiment 3.
Rate
(g N/m
2
) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m) pH EC (dS/m)
13-13-13 Peafowl? 4.9 7.1 ab 0.42 ab 6.8 ab 0.52 ab 7.3 a 0.45 bc 7.5 ab 0.36 b 7.3 a 0.30 abc
13-13-13 Peafowl? 9.8 6.9 bc 0.32 b 6.3 b 0.80 ab 7.1 a 0.37 c 7.1 bc 0.33 b 7.0 a 0.25 bc
13-13-13 Polyon? 4.9 7.3 a 0.37 ab 7.0 a 0.44 b 7.3 a 0.35 c 7.3 ab 0.28 b 7.1 a 0.25 bc
13-13-13 Polyon? 9.8 7.1 abc 0.31 b 6.5 ab 0.37 b 6.9 a 0.32 c 7.2 ab 0.29 b 7.1 a 0.27 abc
CPL
X
4.9 7.2 ab 0.34 b 6.8 ab 0.38 b 7.1 a 0.29 c 7.0 bc 0.27 b 6.9 a 0.24 c
CPL 9.8 7.3 a 0.39 ab 6.7 ab 0.53 ab 7.2 a 0.42 bc 7.7 ab 0.38 b 7.5 a 0.33 abc
CPL 19.6 7.3 a 0.50 ab 6.5 ab 0.60 ab 7.1 a 0.46 bc 7.5 ab 0.39 b 7.4 a 0.34 abc
CPL 29.4 6.8 c 0.68 a 6.6 ab .067 ab 7.0 a 0.39 bc 6.6 c 0.30 b 7.2 a 0.30 abc
CPL 39.2 7.3 a 0.40 ab 6.6 ab 0.82 ab 7.1 a 0.60 ab 7.8 a 0.56 a 7.4 a 0.42 a
CPL 49 7.4 a 0.43 ab 6.8 ab 0.98 a 7.1 a 0.80 a 7.7 ab 0.56 a 7.3 a 0.41 ab
Non-fertilized control *** 7.2 ab 0.31 b 7.0 a 0.42 b 7.2 a 0.32 c 7.6 ab 0.30 b 7.1 a 0.24 c
Z
WAP = Weeks after planting. 
Y
Means within column followed by the same letter are not significantly different based on Duncan's Multiple Range Test (alpha = 0.05).
X
CPL = Composted poultry litter.
Treatment 1 WAP
Z
2 WAP 4 WAP 8 WAP 12 WAP
 
 
 
 
 
 
 
 
 
 
110
111 
 
CHAPTER IV 
Final Discussion 
 
 The purpose of these studies was to evaluate composted poultry litter (CPL) as a 
substrate amendment for container plant production, and as an alternative fertilizer for 
landscape annual bedding plants.  Peat moss (PM) is a relatively non-renewable resource 
and the costs associated with shipping PM from Europe and Canada is continually 
increasing while Pinebark (PB) supplies are becoming less available.  Growers must 
begin to search for alternatives to these two widely used substrate components and find 
new, sustainable, economical, and environmentally friendly substrate components for 
future container plant production.  Fertilizer prices also continue to increase and 
landscapers are searching for cost saving alternatives.  CPL has the potential to provide 
valuable plant nutrients, and where poultry production is concentrated (such as 
Southeastern U.S.), often at a fraction of the cost of inorganic fertilizers.  CPL has 
potential as a suitable alternative substrate amendment while providing valuable plant 
nutrients in container plant production or landscape settings, and therefore could increase 
profit margins for growers and landscapers, while providing poultry producers a new 
avenue for waste disposal, and alleviate the negative environmental impacts associated 
with mass land-application of poultry litter.
112 
 
 In chapter 2 we began to evaluate CPL as an amendment for container plant 
production, more specifically for substrates containing high wood content.  In general, 
most species grew as well or better in substrates containing CPL when compared to the 
industry standard substrate PB:Peat.   Treatment differences did occur among individual 
species, however all treatments provided commercially acceptable plants.   Plants grown 
in substrates containing WholeTree (WT) and clean chip residual (CCR) both of which 
contain high wood content, did not appear to suffer from nitrogen immobilization which 
is often a concern when using a substrate containing a high percentage of wood.  Species 
which grew better in substrates containing CPL, such as boxwood, may have benefitted 
more from the increased pH levels than the additional N levels in the CPL.  Increased EC 
levels in first week after potting did not appear to have any negative effects on plant 
growth, and EC levels dissipated quickly.  However, plants evaluated in these studies 
were woody ornamentals, and most would not be considered ?sensitive? species.  More 
sensitive crops, or herbaceous annuals or perennials could possibly be negatively 
impacted by high pH and EC levels resulting from the addition of CPL.  In these studies, 
azaleas grew better in substrates that did not contain CPL, likely due to increased pH 
levels from the incorporation of CPL.  CPL will never fully replace inorganic fertilizer 
sources for container production, but could possibly supplement these fertilizers while 
providing beneficial physical properties comparable to peat moss at a fraction of the cost, 
depending on the grower?s location.  Results from these studies indicate that use of CPL 
in container production could provide growers an economical and sustainable substrate 
amendment to supplement inorganic fertilizer use, and also provide growers with a peat 
113 
 
substitute while growing non-sensitive crops.  Before growers begin to implement 
composted products of any kind into their production cycle, manures and other composts 
must be tested to provide a known nutrient value of the product, and to ensure a fully 
composted and stable product that is safe for use in container production. 
 In chapter 3, we continued to evaluate CPL as a fertilizer in a series of field 
studies simulating an urban landscape.  Petunias, verbena, and dusty miller were planted 
in raised beds and fertilized with either CPL or a commercially available inorganic 
fertilizer and were evaluated on growth and leaf chlorophyll content (LCC).  Nitrogen 
leaching (NO
3
 and NH
4
) into the soil in the weeks following fertilization was also 
monitored by taking soil water samples using suction cup lysimeters.  Similarities among 
treatments in these studies indicate that CPL could be used effectively in the landscape as 
a fertilizer for annual bedding plants.  In all three experiments, all species grew as large 
or larger when fertilized with CPL as compared to inorganic fertilizers at the same N rate.  
Both petunia and verbena tended to increase in size as the rate of CPL increased.  LCC 
was also comparable among all treatments for the three species tested.  Soil water 
samples also indicate that when applied at the same N rate, CPL leaches less N into soil 
water than inorganic fertilizers.  In addition, even when CPL was applied at N rates 
several times greater than the inorganic fertilizers, little or no difference occurred with 
respect to N leaching.  These results indicate that CPL can be used successfully as an 
alternative fertilizer source for annual bedding plants.  In most cases, the higher rates of 
N applied via CPL also increased plant growth and LCC, while causing minimal or no 
difference in nutrient leaching.  Based upon these studies, landscapers could apply CPL 
114 
 
at much higher rates than inorganic fertilizers, resulting in larger, greener plants while 
causing N leaching comparable to inorganic fertilizers applied at a fraction of the N rate.  
Based upon location and proximity to large poultry operations, landscapers could 
purchase CPL for less than commercially available inorganic fertilizers, and in turn 
increasing profit margins.  While use of CPL in the landscape industry has advantages, 
problems could possibly arise with use in a landscape setting.  While CPL is relatively 
dry and easier to handle than raw litter, N content usually ranges from 1.5 to 3.0%, 
meaning large amounts of CPL would have to be applied to provide the same nutrient 
value as a very small amount of inorganic fertilizers.  Composting also reduces most of 
the odor associated with poultry litter, but some odor will still persist, making CPL 
undesirable in some homeowner and commercial landscape situations.  While 
homeowners are becoming more environmentally aware and are increasing use of 
composted organic products, in some sectors there is still a negative stigma associated 
with spreading animal waste in close proximity to homes or office buildings.  Also, CPL 
would not be economical if the landscape company had to pay fuel costs associated with 
shipping litter long distances, which restricts use of CPL to areas where poultry 
production is concentration, such as the Southeastern United States.  However, as 
fertilizer prices continue to rise homeowners and landscapers will begin to look for less 
expensive fertilizer sources.  CPL could provide nutrients essential to plant growth, while 
providing poultry producers a new avenue for waste disposal, which would hopefully 
benefit the landscape and poultry industries economically, while minimizing negative 
impacts on the environment. 
115 
 
   In addition to these studies, we also evaluated CPL as a fertilizer for ?Meyer? 
zoysia (Zoysia japonica ?Meyer? (Z-52)) turf.  On June 6, 2007, prior to zoysia sod 
installation, five fertilizer treatments were applied to 46.5 m
2
 (500 ft
2
) plots of bare 
ground (no previous fertilization).  Treatments consisted of Osmocote
?
 13N-5.6P-10.9K 
(13-13-13) (The Scott?s Co., Marysville, OH) at 12.2 g nitrogen (N)/m
2 
(2.5 lb N per 
1000 ft
2
), composted poultry litter (CPL) at (12.2 g N/m
2 
(2.5 lb N per 1000 ft
2
), CPL at 
24.2 g N/m
2 
(5 lb N per 1000 ft
2
), and CPL at 36.6 g N/m
2 
(7.5 lb N per 1000 ft
2
).  A non-
fertilized control was also maintained for comparison.  On June 7, 2007, zoysia sod 
(Beck?s Turf, Inc., Tuskegee, AL) was laid on the treated plots in full sun and received 
overhead irrigation as needed.  The five treatments were arranged in a completely 
randomized block design with 3 replications of each treatment.  Leaf chlorophyll content 
(LCC) was taken at 4, 8, 12, 16, and 20 weeks after planting (WAP) using a SPAD-502 
Chlorophyll Meter (Minolta, Inc.).  On May 23, 2008, zoysia was again reevaluated and 
final LCC were taken and foliar color ratings (FCR) were taken on a scale of 1 to 5 with 
1 = brown foliage, 2 = light brown foliage, 3 = light green foliage, 4 = green foliage, 5 = 
dark green foliage. 
 At 4 WAP, there were no differences in LCC of the grass in any of the plots 
receiving fertilizer, a trend that continued at 8 WAP.  At 12 WAP, all fertilizer treatments 
had similar LCC with the exception of CPL (12.2 g N/m
2
) which was significantly higher 
than osmocote at 12.2 g N/m
2
 and CPL at 24.4 g N/m
2
.  By 16 WAP, the osmocote 
treatment had the highest LCC, however LCC was similar to CPL at 24.4 and 36.6 g 
N/m
2
.  The Osmocote treatment again had the highest LCC at 20 WAP, however all 
116 
 
treatments were statistically similar with the exception of the non-fertilized control, 
which had significantly lower LCC than the fertilized zoysia plots.  Zoysia was again re-
evaluated on May 23, 2008 and LCC data and FCR indicated no difference among any 
treatment.  LCC were similar among all treatments and all treatments received a FCR of 
4, with no visual differences seen. 
 Results from this study indicate that CPL has the potential to provide turf 
managers as well as homeowners a fertilizer alternative to expensive inorganic CRFs.  
Minor differences occurred throughout the study, however all fertilizer treatments 
resulted in acceptable zoysia growth and color.  Turf managers could potentially benefit 
economically from incorporating CPL into their fertilization program depending on 
location and proximity to poultry farms.  Turf species are in general heavy feeders of 
nutrients and require numerous applications throughout the growing season.  The layout 
of most sod farms would also make application possible with current spreading 
equipment.  In addition, fast growing turf species would utilize nutrients rapidly; 
reducing leaching and contamination of near-by water supplies. 
 In summary, the results from these experiments demonstrate that composted 
poultry litter could be used successfully as an amendment in container plant production 
as well as an alternative fertilizer source for landscape annual bedding plants and lawns.  
In container production, CPL could be used as a substitute for peat for non-sensitive 
crops, while providing growers a cheap source of nutrients.  In a landscape setting, CPL 
could provide a fertilizer source that performs as well as most commercially available 
fertilizers at a fraction of the cost.  In addition, much higher rates of N could be applied 
117 
 
without causing excessive N leaching, resulting in larger, more attractive plants. 
Incorporating the use of CPL into the horticulture industry could provide economic 
benefits to growers and landscapers, provide poultry producers a new way to dispose of 
poultry manure, and help mitigate negative impacts that land application of poultry litter 
has on the environment.