? ? Nitrogen?Release?Characteristics?of?Commercial?Organic?Fertilizers?in?Turfgrass? by? Brandon?Dale?Green? ? ? 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? August?6,?2011? ? ? Keywords:?nitrogen,?mineralization,?ammonium,?nitrate,?bermudagrass,?organic,?fertilizer? ? Copyright?2011?by?Brandon?Dale?Green? ? Approved?by? Elizabeth?A.?Guertal,?Chair,?Professor?of?Agronomy?and?Soils? C.?Wesley?Wood,?Professor?of?Agronomy?and?Soils? Julie?A.?Howe,?Assistant?Professor?of?Agronomy?and?Soils ? ii? ? Abstract? ? ? ? Although?organic?fertilizer?sources?are?widely?marketed?for?application?to?turfgrasses,? there?is?limited?research?that?examines?their?nitrogen?(N)?release?characteristics.??For?this? research?project,??organic??refers?to?commercial?fertilizers?which?are?manufactured?from?wastes? such?as?sewage?sludge?(bio?solid),?poultry?by?products?(manure,?litter,?feather?meal),?or?other? by?products?(whey,?meals,?oils).??The?process?of?mineralization,?which?is?the?microbially? mediated?conversion?of?organic?N?to?plant?available?ammonium?N?(NH4)?and?nitrate?N?(NO 3 )? forms,?is?the?controlling?factor?of?N?release?from?organic?fertilizers.??Thus,?organic?fertilizers? behave?as?a?slow?release?N?fertilizer,?with?a?delayed?greening?response,?low?burn?potential,?and? varying?N?release?rates?in?different?environments.??Of?the?environmental?variables,?temperature? has?perhaps?the?greatest?effect?on?microbial?activity,?which?in?turn?controls?inorganic?N?release? from?the?organic?sources.??Although?N?mineralization?from?raw?wastes?such?as?manure?or?bio? solids?has?been?widely?studied,?N?release?from?processed,?commercially?blended?organic? fertilizers?has?been?less?studied,?especially?in?turfgrass?systems.? Two?separate?three?month?studies?evaluated?the?effects?of?organic?fertilizers?on?hybrid? bermudagrass?growth?and?performance.??In?general,?application?of?sources?with?large?portions? (or?100%)?of?soluble?N?(urea?and?Scotts?Turf?Builder)?produced?turf?with?a?darker?green?color,? higher?shoot?density?and?greater?clipping?yield?than?plots?fertilized?with?large?portions?of?organic? N.??Although?organic?fertilizers?are?often?touted?as?maintaining?color?for?longer?periods?of?time,? it?was?not?the?case?in?this?study,?as?urea?provided?consistent?high?quality?color?for?the?same?8?10? ? iii? ? week?period?as?the?organic?sources.??There?were?few?differences?in?soil?N,?C,?or?microbial? biomass?due?to?N?source. Six?individual?ten?week?incubation?studies?(two?repetitions?per?temperature)?were? performed?at?15,?25,?and?35?C.??Mineralization?of?organic?N?was?measured?and?it?was? significantly?affected?by?treatment?and?a?treatment?x?temperature?interaction.??Optimum? inorganic?N?release?was?observed?at?25?C,?with?the?least?amount?of?N?mineralization?occurring?at? 15?C.??Ammonium?N?was?largely?produced?during?the?first?two?weeks?after?application,?and?then? converting?to?mostly?NO 3 ?N.? iv? ? Acknowledgments? ? ? ? I?would?like?to?first?thank?Dr.?Guertal?for?the?opportunities?she?has?bestowed?on?me.??I? thank?you?for?all?the?hard?work?you?have?endured?through?your?career?to?allow?me?this? opportunity.??I?also?would?like?to?thank?my?graduate?committee,?Drs.?Wood?and?Howe,?for?their? time?and?guidance.??A?special?thanks?to?Bill?Bryce,?Brenda?Wood,?Jim?Harris?and?their?staff?for?all? their?dedicated?hard?work?in?the?laboratory?and?field.???Finally,?I?would?like?to?thank?my?family? and?friends?for?their?patience?and?support?throughout?my?time?at?Auburn.? ? ? ? v? ? Table?of?Contents? ? ? Abstract?............................................................................................................................................?ii? Acknowledgments...........................................................................................................................?iv? List?of?Tables?...................................................................................................................................?vii? List?of?Figures?...................................................................................................................................?ix? Literature?Review?.............................................................................................................................?1? ? Introduction?........................................................................................................................?1? ? Wastes?in?Agriculture?..........................................................................................................?2? ? Nutrients?in?Animal?Wastes?................................................................................................?5? ? Importance?of?Nitrogen?......................................................................................................?8? ? Fate?of?Nitrogen?..................................................................................................................?9? ? Turfgrass?and?Nitrogen?.....................................................................................................?14? ? Common?Nitrogen?Fertilizers?............................................................................................?16? ? Organic?Nitrogen?in?Turf?...................................................................................................?18? ? Study?Objectives?...............................................................................................................?19? Materials?and?Methods?..................................................................................................................?20? ? Field?Study?.........................................................................................................................?20? ? Laboratory?Incubation?Study?............................................................................................?22? Results?and?Discussion?...................................................................................................................?24? ? Field?Study?.........................................................................................................................?24 ? vi? ? ? Fertilizer?Removal?................................................................................................?24? ? Turf?Color?Response?.............................................................................................?25? ? Clipping?Yield?and?Tissue?Nitrogen?......................................................................?27? ? Soil?Nitrogen,?Carbon,?and?Soil?Microbial?Biomass?..............................................?28? ? Roots,?Shoots,?and?Rhizomes/Stolons?.................................................................?30? Laboratory?Incubation?Study?............................................................................................?31? ? Mineralization?......................................................................................................?31? Summary?........................................................................................................................................?34? Literature?Cited?..............................................................................................................................?35? ? vii? ? List?of?Tables? ? ? Table?1.?Initial?soil?test?value?(Mehlich?1?extractant)?for?the?two?research?areas,?TGRU,?Auburn,? Al.??..................................................................................................................................................?44? Table?2.?Maintenance?fertilizer,?fungicides,?and?herbicides?applied?to?the?two?field?studies,? TGRU,?2009?and?2010.?...................................................................................................................?45? Table?3.?Selected?fertilizer?treatments?used?in?both?laboratory?incubation?and?field?research? studies.??..........................................................................................................................................?46? Table?4.?Organic?ingredients?in?selected?fertilizer?treatments?used?in?both?laboratory?incubation? and?field?research?studies.??............................................................................................................?47? Table?5.?Fertilizer?pickup?by?mower?(g?per?plot)?as?affected?by?N?source,?2010,?Auburn,?AL.??.....?48? Table?6.?Visual?color?ratings?(1:brown?9:dark)?of?hybrid?bermudagrass?as?affected?by?N?source,? 2009,?Auburn,?AL.??..........................................................................................................................?49? Table?7.?Visual?color?ratings?(1:brown?9:dark)?of?hybrid?bermudagrass?as?affected?by?N?source,? 2010,?Auburn,?AL.??..........................................................................................................................?51? Table?8.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,? Auburn,?AL.??....................................................................................................................................?53? Table?9.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,? Auburn,?AL.??....................................................................................................................................?55? Table?10.?Clipping?yield?(grams?per?plot)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,? Auburn,?AL.??....................................................................................................................................?57? Table?11.?Clipping?yield?(grams?per?plot)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,? Auburn,?AL.??....................................................................................................................................?58? Table?12.?Tissue?N?(g?N?per?kg?tissue)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,? Auburn,?AL.?....................................................................................................................................?59?? Table?13.?Tissue?N?(g?N?per?kg?tissue)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,? Auburn,?AL.??....................................................................................................................................?60?? ? viii? ? Table?14.?Inorganic?N?(mg?N?per?kg?soil)?(NH 4 ?N?+?NO 3 ?N)?(2M?KCl?extract)?soil?content?as? affected?by?N?source,?2009,?Auburn,?AL.??......................................................................................?61 Table?15.?Ammonium?N?(mg?N?per?kg?soil)?(NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N? source,?2009,?Auburn,?AL.??.............................................................................................................?63? Table?16.?Nitrate?N?(mg?N?per?kg?soil)?(NO3?N)?(2M?KCl?extract)?soil?content?as?affected?by?N? source,?2009,?Auburn,?AL.??.............................................................................................................?64? Table?17.?Inorganic?N?(mg?N?per?kg?soil)?(NH 4 ?N?+?NO 3 ?N)?(2M?KCl?extract)?soil?content?as? affected?by?N?source,?2010,?Auburn,?AL.??......................................................................................?65? Table?18.?Ammonium?N?(mg?N?per?kg?soil)?(NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N? source,?2010,?Auburn,?AL.??.............................................................................................................?66? Table?19.?Nitrate?N?(mg?N?per?kg?soil)?(NO 3 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N? source,?2010,?Auburn,?AL.??.............................................................................................................?67? Table?20.?Total?soil?N?((inorganic?+?organic)?g?N?per?kg?soil)?of?hybrid?bermudagrass?as?affected? by?N?source,?2009,?Auburn,?AL.??.....................................................................................................?68? Table?21.?Total?soil?N?((inorganic?+?organic)?g?N?per?kg?soil)?of?hybrid?bermudagrass?as?affected? by?N?source,?2010,?Auburn,?AL.??.....................................................................................................?69? Table?22.?Soil?C?(g?C?per?kg?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,? AL.??.................................................................................................................................................?70? Table?23.?Soil?C?(g?C?per?kg?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,? AL.??.................................................................................................................................................?71? Table?24.?Soil?microbial?biomass?(ug?C?per?g?soil)?of?hybrid?bermudagrass?as?affected?by?N? source,?27?July,?2010,?Auburn,?AL.??................................................................................................?72? Table?25.?Weekly?maximum?and?minimum?temperatures?of?hybrid?bermudagrass?,?2010,? Auburn,?AL.??....................................................................................................................................?73? Table?26.?Root?and?shoot?measurements?(average?of?two?57?mm?diam.?cores)?of?hybrid? bermudagrass?as?affected?by?N?source,?21?July?2009,?Auburn,?AL.??..............................................?74? Table?27.?Root?and?shoot?measurements?(average?of?two?57mm?diam.?cores)?of?hybrid? bermudagrass?as?affected?by?N?source,?2010,?Auburn,?AL.??..........................................................?75? Table?28.?Laboratory?mineralization?study?analysis?of?variance,?2009?and?2010,?Auburn,?AL.??....?76? Table?29.?Simulated?P?values?for?organic?fertilizer?treatments?used?in?mineralization?study,?2009? and?2010,?Auburn,?AL.??...................................................................................................................?77? Table?30.?Join?day?and?percent?recovery?for?mineralization?study,?2009?and?2010,?Auburn,?AL.??78? Table?31.Weekly?maximum?and?minimum?air?temperatures?for?incubation?study?(15?and?35?C),? 2010.??.............................................................................................................................................?79? ix? ? List?of?Figures? ? ? Figure?1.?Visual?color?rating?(1?to?9)?of?hybrid?bermudagrass?as?affected?by?N?source.?(applied?on? April?27,?2009)?Auburn,?AL.??...........................................................................................................?80? Figure?2.?Visual?color?rating?(1?to?9)?of?hybrid?bermudagrass?as?affected?by?N?source.?(applied?on? May?4,?2010)?Auburn,?AL.??.............................................................................................................?81? Figure?3.?Colorimeter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source.?(applied?on? April?27,?2009)?Auburn,?AL.??...........................................................................................................?82? Figure?4.?Colorimeter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source.?(applied?on? May?4,?2010)?Auburn,?AL.??.............................................................................................................?83? Figure?5.?Correlation?between?visual?color?and?chlorophyll?meter?readings?as?affected?by?N? source,?2009,?Auburn,?AL.??.............................................................................................................?84? Figure?6.?Correlation?between?visual?color?and?chlorophyll?meter?readings?as?affected?by?N? source,?2010,?Auburn,?AL.??.............................................................................................................?85? Figure?7.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?urea?application?to?a? Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C?(bottom),? respectively.??..................................................................................................................................?86? Figure?8.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?Milorganite?application?to? a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C?(bottom),? respectively.??..................................................................................................................................?87? Figure?9.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?NatureSafe?Starter? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.??..................................................................................................................?88? Figure?10.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?NatureSafe?StressGuard? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.??..................................................................................................................?89? Figure?11.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?Sustane??(4?6?4)? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.??..................................................................................................................?90? x? ? Figure?12.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?TOP?(fine?grade)? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.??..................................................................................................................?91? Figure?13.?Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?TOP?(regular?grade)? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.??..................................................................................................................?92? Figure?14.?Percent?of?inorganic?N?(NH 4 ?N?+?NO 3 ?N)?recovery?from?organic?fertilizer?sources? applied?to?a?Marvyn?loamy?sand?incubated?at?15?C,?2009?and?2010,?Auburn,?AL.?.......................?93? Figure?15.?Percent?of?inorganic?N?(NH 4 ?N?+?NO 3 ?N)?recovery?from?organic?fertilizer?sources? applied?to?a?Marvyn?loamy?sand?incubated?at?25?C,?2009?and?2010,?Auburn,?AL.??......................?94? Figure?16.?Percent?of?inorganic?N?(NH 4 ?N?+?NO 3 ?N)?recovery?from?organic?fertilizer?sources? applied?to?a?Marvyn?loamy?sand?incubated?at?35?C,?2009?and?2010,?Auburn,?AL.??......................?95? Figure?17.?Day?70?percent?recovery?of?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?from?organic?fertilizer? sources?applied?to?a?Marvyn?loamy?sand?incubated?at?15,?25,?and?35?C,?Auburn,?AL.??................?96 1? ? Literature?Review? ? Introduction? The?early?19 th ?century?sparked?a?new?revolution?in?fertilization?technology,?when?the? first?chemically?produced?fertilizer,?superphosphate,?was?made?from?bones?treated?with?sulfuric? acid.?The?first?synthetic?nitrogen?(N)?fertilizer?was?produced?in?1903?by?the?electric?arc?process,? which?converted?nitric?acid?into?calcium?nitrate.??Ten?years?later?synthetic?ammonia?(NH 3 )? became?widely?available?(Russel?and?Williams,?1977).??Chemical?fertilizers?have?made?a?major? impact?on?agriculture,?allowing?for?greater?yields?of?crops?and?more?aesthetically?pleasing? ornamentals?and?turfgrass?(Sheridan,?1979).??? Chemically?produced?fertilizers?have?proven?to?be?beneficial,?but?are?by?no?means?the? only?option.??The?expense?of?these?products,?coupled?with?a?global?economy?in?which?fertilizer? prices?are?increasing,?has?directed?attention?to?alternative?fertilizer?sources.??Renewed?interest? in?recycling?and?natural?product?usage?has?increased?interest?in?the?reuse?of?industrial?waste? products,?including?municipal?solid?wastes,?processing?wastes,?bio?solids,?manures,?and?other? materials?that?would?otherwise?find?their?way?into?landfills.??? Organic?waste?products?have?been?studied?in?row?crop?production,?but?research?on?their? utility?for?turfgrass?fertilization?is?limited.??With?increasing?marketing?of?new?organic?products?in? the?turfgrass?industry,?research?is?needed?to?support?the?benefits?of?many?of?these?products.??In? 2? ? order?to?evaluate?a?waste?product?for?its?potential?as?a?fertilizer,?it?is?critical?to?know?its?nutrient? release?characteristics.??? Several?methods?have?been?used?to?evaluate?nutrient?release?characteristics?in?organic? wastes?(Balkcom?et?al.,?2001;?Mamo?et?al.,?1999;?Carrow,?1997).??Organic?products?are?often? slow?to?break?down?and?release?nutrients.??He?et?al.?(2000)?observed?a?23.5?and?48.4%?recovery? of?added?N?at?the?end?of?a?one?year?experiment?using?yard?waste?and?bio?solid?composts.?? Nadelhoffer?(1990)?studied?organic?products?using?a?microlysimeter?system,?and?was?able?to? obtain?reproducible?N?release?measurements?with?experiments?lasting?45?weeks.??These?types?of? studies,?coupled?with?field?studies?that?examine?variables?such?as?turf?color,?density,?and? growth,?provide?a?thorough?investigation?of?the?effect?of?organic?fertilization?on?turf.? ?Wastes?in?Agriculture? The?term?waste?generally?carries?a?negative?connotation;?however,?research?studies? have?shown?that?the?reuse?of?some?waste?products?can?have?a?positive?impact?on?our? environment.??An?EPA?survey?reported?that?a?total?of?226?million?Mg?of?municipal?solid?waste? (yard?trimmings,?food,?and?packaging?wastes)?was?generated?in?2008,?of?which?only?33.1?million? Mg?were?recycled?(EPA,?2008).??Typically?67%?of?the?municipal?solid?waste?in?the?United?States?is? placed?in?a?landfill,?23%?is?recycled,?and?10%?is?incinerated?(Entry?et?al.,?1997).?? The?increasing?cost?of?safe?disposal?of?municipal?solid?waste?in?landfills?is?one?reason?for? renewed?interest?in?application?of?organic?by?products?to?agricultural?lands.??Municipal?solid? wastes?have?variable?carbon?(C)?to?N?ratios,?which?strongly?controls?the?rate?of?nutrient?release? (Mamo?et?al.,?1999;?Sims,?1990).??Studies?have?shown?that?municipal?solid?wastes?can?supply?a? sufficient?amount?of?N?for?plant?growth?as?well?as?small?amounts?of?phosphorus?(P),?potassium? 3? ? (K),?calcium?(Ca),?magnesium?(Mg),?sulfur?(S),?and?iron?(Fe)?(Warman?et?al.,?2009;?Mamo?et?al.,? 1999).??Trace?elements?including?copper?(Cu),?manganese?(Mn),?zinc?(Zn),?boron?(Bo),?cadmium? (Cd),?chromium?(Cr),?nickel?(NI),?and?lead?(Pb)?were?also?present?(Warman?et?al.,?2009;?Meima? and?Comans,?1999).?? Waste?products?encompass?much?more?than?household?garbage.??Metals?and?fuel?drive? western?economies?today,?and?with?as?much?of?these?resources?being?used,?there?are?by? products?requiring?disposal.??Precious?metals?and?coal?are?probably?the?two?most?important? resources?used?today?which?require?mining.??Mining?operations?are?intensive?and?have?large? impacts?on?the?local?areas?surrounding?these?mines,?as?the?United?States?has?1,458?coal?mines? that?produced?about?1.1?million?Mg?of?coal?in?2008?(U.?S.?Department?of?Energy,?2008).??? Coal?powered?plants?create?a?residue?known?as?fly?ash.??Belyaeva?and?Hayes?(2009)? observed?that?a?25%?fly?ash?addition?to?green?manure?increased?water?retention?by?75%.?? Hermann?et?al.?(2009)?examined?fly?ash?in?landfill?cover?liners.??Fly?ash?was?mixed?with?sewage? sludge?and?placed?under?2.4?J?cm ?3 ?of?pressure.??Hydraulic?conductivity?was?between?1.7?X?10 ?11 ? and?8.9?X?10 ?10? m?s ?1 ,?which?met?the?hazardous?waste?landfill?cover?requirement?of?less?than?10 ?9? m?s ?1 .? When?metal?is?extracted?from?ore,?the?by?product?that?is?produced?is?known?as?slag.??For? every?0.9?Mg?of?steel?produced,?roughly?150?kg?of?slag?is?generated.??Slag?has?been?shown?to? have?high?concentrations?of?Ca?(29%)?and?Mg?(5%),?which?indicates?its?use?as?a?potential?liming? agent.??Rodriguez?et?al.?(1994)?observed?that?the?highest?application?of?slag?(7,500?kg?ha ?1 )?raised? the?pH?of?the?soil?from?5.3?to?6.5.??Pierre?(1927)?quantified?the?amount?of?slag?needed?to?correct? acidity?developed?from?applying?nitrogenous?fertilizers?and?found?that?1?kg?of?slag?was?required? 4? ? to?correct?the?acidity?formed?from?0.45?kg?of?ammonium?sulfate?((NH 4 ) 2 SO 4 ),?and?1.5?2.2?kg?of? slag?offered?the?same?effect?as?0.45?kg?of?calcium?carbonate?(CaCO 3 ).??Slag?is?also?known?to?have? high?concentrations?of?phosphate,?and?will?increase?plant?concentrations?of?Ca,?Mg,?and?P,?while? lowering?K?and?Mn?(Rodriguez?et?al.,?1994).??Other?benefits?of?slag?usage?include?aiding?in?P? removal?from?wastewater?and?reducing?methane?emission?from?rice?fields?(Pratt?et?al.,?2008;?Ali? et?al.,?2008).?? However,?many?waste?products,?such?as?fly?ash,?municipal?solid?waste,?and?animal? manures?have?high?concentrations?of?heavy?metals,?specifically?Cu,?Cr,?Pb,?Zn,?and?Ag,?which? have?the?potential?to?contaminate?ground?and?surface?waters?(Chandler?et?al.,?1997;?Hargreaves? et?al.,?2007;?Del?Castilho?et?al.,?1993).??In?Alabama,?a?1999?survey?reported?that?1.5?million?Mg?of? broiler?litter?was?produced?and?mainly?applied?as?an?organic?fertilizer;?however,?elevated?levels? of?As,?Cd,?Co,?and?Cr?in?the?litter?may?cause?additional?agronomic?management?issues? (Kpomblekou?et?al.,?2002)..??? Prior?to?the?1840?s,?farmers?used?manures,?wood?ashes,?and?bones?as?sources?of?crop? nutrients.??In?1843,?the?first?widely?used?commercial?fertilizer?in?the?United?States?was?derived? from?Peruvian?guano,?containing?large?amounts?of?N?and?P?(Sheridan,?1979).??In?the?United? States,?an?increased?demand?for?animal?products?has?resulted?in?greater?animal?and?animal? processing?wastes,?including?manure,?litter,?tankage,?and?feather,?bone,?and?blood?meal.?? Concentrated?animal?feeding?operations?(CAFO)?maintain?large?numbers?of?livestock?in?small? areas?of?land.??The?amount?of?waste?that?accumulates?in?these?CAFO?s?is?large,?and?disposing?of? these?products?safely?has?become?burdensome?and?expensive.??Using?these?waste?products?as? fertilizers?has?become?a?renewed?practice,?and?is?growing?in?popularity.?? 5? ? ? Cattle?and?poultry?manures?are?two?of?the?most?frequently?used?materials?for?organic? fertilizers.??A?study?comparing?the?effects?of?dairy?manure?and?inorganic?fertilizers?to?turfgrass? showed?a?significant?increase?in?soil?organic?matter?with?dairy?manure?compost.??Soils?with? applied?manure?compost?showed?increases?in?electrical?conductivity,?pH,?and?overall?soil? nutrient?levels?(Butler?et?al.,?2008).??A?study?of?dairy?and?poultry?manure?compost?applications?to? Kentucky?bluegrass?(Poa?pratensis)?and?perennial?ryegrass?(Lolium?perenne)?resulted?in?higher? turf?quality?as?compared?to?the?non?treated?and?inorganic?fertilizer?treatments.??The?researchers? concluded?that?manures?may?have?a?beneficial?long?term?effect?(Petrovic?et?al.,?2008).??The? nutrient?content?and?release?characteristics?of?manures?are?highly?variable?and?require?research? to?assess?their?agronomic?benefits?and/or?limitations.?? Nutrients?in?Animal?Wastes?? ?Organic??in?the?simplest?form?means?that?a?compound?contains?C;?however,?fertilizer? products?that?are?made?from?animal?by?products?are?generally?referred?to?as??organic??fertilizers.?? From?here?on,?the?term?organic?will?be?used?to?signify?a?fertilizer?that?contains?C?and?are?derived? from?recycled?animal?wastes.??Many?organic?fertilizers?are?derived?from?animal?excrement,?such? as?poultry?litter?and?cow?manure,?but?also?contain?by?products?such?as?bone,?feather,?and?blood? meals.??Poultry?litter?may?provide?plant?macro?and?micronutrients,?but?additives?such?as?feather,? bone,?and?blood?meal?are?used?to?augment?the?overall?fertilizer?nutrition?(King?and?Torbert,? 2007).? Organic?N?can?only?be?absorbed?by?the?root?after?conversion?to?inorganic?N?by?the? process?of?mineralization.??Ammonification,?the?first?step?in?mineralization,?is?an?enzymatic? process?in?which?soil?microbes?actively?breakdown?organic?N?compounds?into?ammonia?(NH 3 )? 6? ? and?ammonium?(NH 4 ).??This?is?performed?by?both?aerobic?and?anaerobic?microorganisms?that? cause?an?enzymatic?oxidation?(Eldridge?et?al.,?2008).???Following?ammonification,?NH 3 ?can?be? further?oxidized?in?the?second?process?of?nitrification.??In?nitrification,?Nitrosomonas?and? Nitrobacter?are?the?two?most?crucial?N?oxidizing?bacteria.??Nitrosomonas?oxidizes?NH 3 ?to?nitrite? (NO 2 ),?while?Nitrobacter?converts?NO 2 ?to?NO 3 .??These?bacterial?colonies?can?be?found?in?higher? concentrations?than?other?soil?nitrifiers?(Belser?and?Schmidt,?1978).? Bio?solids?typically?have?3.5?6%?total?N,?and?80?90%?is?in?the?organic?form?(Eldridge?et? al.,?2008).??The?N?in?these?products?is?largely?organic?N,?and?must?be?mineralized?to?be?plant? available.??Compost?and?bio?solids?have?been?shown?to?increase?the?concentration?of?microbial? biomass?in?the?root?zone,?as?well?as?soil?contents?of?organic?N?and?C?(Tian?et?al.,?2008;?Hartl?and? Erhart,?2005).??Addition?of?organic?fertilizers?increased?total?bacterial?counts?within?4?days?of? application,?and?nitrifier?populations?were?three?times?more?prevalent?in?fertilized?soils?(Li,? 2005;?Hermansson?and?Lindgren,?2001).????? Golf?course?superintendents?typically?apply?large?amounts?of?N?fertilizer?in?order?to? maintain?high?quality?playing?surfaces?(Brown?et?al.,?1982).??Application?of?inorganic?fertilizers,? such?as?ammonium?nitrate?(NH 4 NO 3 ),?can?result?in?NO 3 ?leaching?into?groundwater?due?to?the? abundant?amount?of?highly?soluble?N?that?exceeds?plant?uptake?ability.??Given?their?slow?release? nature,?organic?waste?fertilizers?may?be?one?solution?to?these?problems.??When?nutrients?such?as? N?and?P?are?bound?by?organic?matter,?they?are?less?susceptible?to?losses?through?surface?runoff? and?leaching?(Balkcom?et?al.,?2001).??They?are?slowly?mineralized?and?become?available?to?the? plant.??Turkey?litter,?for?example,?showed?less?than?1%?N?loss?due?to?leaching?from?a?top?dress? application?(Johnson?et?al.,?2006).??Cumulative?NO 3 ?loss?from?plots?of?bermudagrass?[Cynodon? 7? ? dactylon?(L)?Pers.],?showed?significantly?less?NO 3 ?loss?from?plots?receiving?poultry?and?dairy? manures?than?NH 4 NO 3? (King?and?Torbert,?2007).? Soils?amended?with?organic?N?have?improved?physical,?chemical,?and?microbiological?soil? properties?(Entry?et?al.,?1997).??Organic?fertilizers?increased?soil?organic?matter,?which?increased? water?holding?capacity,?soil?aggregation,?soil?aeration?and?permeability,?while?decreasing?bulk? density?(Johnson?et?al.,?2006).??Although?there?are?beneficial?qualities?of?organic?fertilizers?in? plant?production,?there?are?also?negative?issues.??Carrow?(1997)?concluded?that?no?single?organic? fertilizer?contained?the?most?desired?mix?of?immediate?and?long?term?N?release?characteristics.?? Organic?fertilizers?generally?have?a?low?nutrient?analysis?and?thus?need?larger?application?rates? to?reach?desired?fertility?recommendations.??Organics?are?accompanied?by?a?noticeable?odor?and? have?pesticide?sorption?tendencies?that?could?pose?a?problem,?especially?for?applications?on?golf? courses?(Li,?2005).??? Poultry?litter?has?an?average?N?to?P?ratio?of?3:1,?and?when?applied?on?a?N?basis,?it? delivers?more?P?than?most?agronomic?crops?can?utilize?(Moore?et?al.,?1995;?Pote?et?al.,?1996).?? Long?term?applications?of?poultry?litter?can?result?in?P?runoff.??Surface?applied?fertilizers?typically? have?the?greatest?P?runoff,?which?occurs?within?the?first?24?hours?after?application?(Baker?et?al.,? 2007;?Shuman,?2002).??Phosphorus?runoff?may?lead?to?eutrophication?of?lakes?and?streams,? eventually?igniting?algal?blooms?that?lead?to?subsequent?fish?kills?(Sharpley?et?al,?2003).???Pote?et? al.?(1996)?looked?at?P?runoff?from?swine,?broiler,?caged?litter,?and?manure?sources?at?P? application?rates?ranging?from?0?to?304?kg?P?ha ?1 .??Concentrations?of?P?in?runoff?samples?taken?30? minutes?after?application?were?0.31?to?1.81?mg?L ?1 ?of?dissolved?reactive?P?and?0.37?to?2.18?mg?L ?1 ? of?bio?available?P.?? 8? ? Importance?of?Nitrogen? Nitrogen?is?crucial?for?plant?chlorophyll,?proteins,?and?amino?acids.??The?N?requirement? for?individual?plant?species?varies?greatly?depending?on?the?plant?itself?(Petrovic,?1990).??Plant? uptake?of?N?is?mainly?through?the?root?system?and?is?also?a?function?of?N?availability?and? concentration?(Petrovic,?1990).??Turfgrass?quality?is?largely?controlled?by?N.??It?has?been?shown? that?sufficient?N?must?be?applied?to?turf?annually?to?maintain?shoot?growth,?recuperative? potential,?color,?and?quality?(Kerek?et?al.,?2003).?? ?High?N?uptake?has?been?correlated?with?periods?of?high?color?intensity?and?clipping?yield? (Landschoot?and?Waddington,?1987).??Once?N?has?been?absorbed?through?the?roots?and?utilized? in?the?plant,?overall?plant?available?N?in?the?soil?becomes?deficient?and?the?turfgrass?requires? additional?N?to?sustain?normal?growth.??When?N?is?lacking,?stunted?growth?and?overall?yellowing? of?the?shoots?occurs.??Bowman?(2003)?discussed?the?importance?of?controlled?daily?N?additions? in?order?to?achieve?stable?growth?and?tissue?N?pools.??Weekly?and?monthly?N?applications?to? perennial?ryegrass?caused?erratic?fluctuations?in?growth?and?tissue?N?pools.??Earlier?studies?on? birch?(Betula?lenta)?and?Salix?showed?that?unexpected?changes?in?daily?N?additions?created? unstable?tissue?N?levels?and?leaf?chlorosis?(Ingstead,?1980?and?1981;?Ericsson,?1981;?Ingstead? and?McDonald,?1989).??Marshall?et?al.?(2001)?observed?43%?N?uptake?in?tall?fescue?fertilized?with? broiler?litter?applied?at?rates?from?103?to?252?kg?N?ha ?1 .??? Plants?take?up?considerable?N?to?maintain?overall?plant?health?and?quality.??Mowing? practices?on?golf?courses,?which?generally?involve?reel?mowers,?are?an?important?source?of?N? loss?via?clipping?removal.??A?study?that?evaluated?clipping?return?showed?that?return?of?clippings? increased?dry?matter?yield?from?30?to?72%,?total?N?uptake?from?48?to?60%,?and?N?use?efficiency? 9? ? from?52?to?71%.??Some?plots?also?showed?an?increase?in?overall?turf?quality?due?to?clipping? return?(Kopp?and?Guillard,?2002).??Fagerness?et?al.?(2004)?applied?NH 4 NO 3 ?to?bermudagrass?at?50? kg?N?ha ?1 ?three?times?over?14?weeks,?and?recovered?65%?of?the?total?N?in?plant?tissue?(clipping,? root,?and?rhizome).??Shi?et?al.?(2006b)?measured?N?mineralization?rates?from?bermudagrass? clippings?in?a?28?day?incubation?study.??They?found?that?20?to?30%?of?N?in?the?clippings?had? mineralized?by?the?end?of?the?incubation?study.??Yao?et?al.?(2009)?measured?total?C?and?N? mineralization?increases?of?58?and?33%,?respectively,?during?a?similar?clipping?return?study?on? bermudagrass?and?perennial?ryegrass.?? Fate?of?Nitrogen? Nitrogen?has?multiple?sources?of?entries?and?outlets?from?which?it?can?enter?the? plant/soil?or?be?lost?to?the?environment.??These?include?mineralization?(ammonification?and? nitrification),?immobilization?(NO 3 ?to?organic?N),?volatilization?(NH 3 ),?denitrification?(NO 2 ,?NO,? and?N 2 ),?plant?uptake,?and?clay?fixation.??Nitrogen?can?accumulate?in?the?soil?from?N?fixation?via? lightning,?plant?decomposition,?organic?wastes,?or?via?the?application?of?fertilizers.??Losses?of?N? from?the?soil?include?plant?uptake,?gaseous?atmospheric?loss,?soil?storage,?leaching,?runoff,?and? clipping?removal?(Petrovic,?1990).??Once?fertilizer?N?is?in?the?soil,?it?becomes?part?of?the?soil? organic?matter,?plant,?or?soluble?N?pool?(NO 3 ?and?NH 4 )?(Kerek?et?al.,?2003).??Bowman?and?Paul? (1992)?observed?a?35%?foliar?absorption?of?N?within?48?hours?of?a?5?g?N?m 2? ?application?of?urea? to?perennial?ryegrass.??The?partitioning?of?N?was?32,?52,?and?16%?amongst?new?leaves,?old?leaves? and?shoot?tissue,?and?roots,?respectively.??? Plants?take?up?N?in?two?forms:?NH 4? and?NO 3 .??When?organic?N?is?applied?to?the?soil,?it? must?first?be?mineralized?to?NH 3 ,?then?protonated?chemically?to?form?NH 4 .??Ammonium?is?fairly? 10? ? stable?in?the?soil?and?its?loss?is?often?negligible?as?the?cation?is?not?prone?to?leaching?(Mazur?and? White,?1983).??Ammonium?can?then?be?converted?into?NO 3 ?via?NO 2 ?in?the?nitrification?process.?? Nitrate,?an?anion,?is?highly?leachable?(Di?and?Cameron,?2002).??Mineralization?of?organic?N?is? influenced?by?several?factors,?including?but?not?limited?to:?N?content?of?compost,?C:N?ratio,?soil? texture,?and?climate?(Hartl?and?Erhart,?2005).??Mineralization?rates?of?N?are?comparable?among? alkaline?and?acidic?soils?(Yao?et?al.,?2009).??High?correlations?between?C?released?as?CO 2 ?and? available?N?have?been?shown?(Castellanos?and?Pratt,?1981).??? Soil?moisture?content?is?a?significant?factor?in?determining?mineralization?rates,?with? measured?mineralization?greatest?at?field?capacity?(Watts?et?al.,?2007).??Soil?temperature?also? affects?mineralization.??Amongst?three?soil?temperatures,?maximum?N?mineralization?occurred? at?25?C,?which?was?3.7?times?faster?than?mineralization?at?15?C,?while?mineralization?at?15?C?was? 13?times?faster?than?at?5?C?(Watts?et?al.,?2007).??There?is?limited?research?that?examines? mineralization?at?temperatures?greater?than?25?C,?but?some?research?suggests?that?maximum? microbial?activity?occurs?between?30?and?35?C?(Jones?and?Hood,?1980;?Fdz?Polanco?et?al.,?1994;? Lee?et?al.,?2001).??? Once?ammonification?has?taken?place,?NH 3 ?is?vulnerable?to?atmospheric?loss?through? volatilization.???Ammonia?volatilization?is?more?prevalent?in?soils?with?higher?pH?values?in?warmer? windier?climates?(Clay?et?al.,?1990;?Ferguson?and?Kissel,?1986).??Mulvaney?et?al.?(2008a)?found? drastic?seasonal?differences?in?NH 3 ?volatilization.??Nitrogen?sources?included?beef?feces,?dairy? feces,?and?dairy?urine.??Ammonia?losses?ranged?from?1.8%?during?the?winter?to?20.9%?during? summer.??Ammonia?loss?through?volatilization?has?been?shown?to?be?highly?variable?and? drastically?reduced?by?watering?immediately?after?application?of?urea?fertilizer?(Petrovic,?1990;? Bowman?et?al.,?1987).??Another?study?suggests?that?less?than?1%?of?added?N?treatments?were? 11? ? lost?as?gaseous?forms?(Burger?and?Venterea,?2008).??Marshall?et?al.?(2001)?observed?a?6%?loss?of? applied?N?from?volatilization?and?denitrification?combined?from?a?boiler?litter?application?to?tall? fescue?(Festuca?arundinacea)?pastures.??When?chicken?litter?was?applied?at?70?kg?N?ha ?1 ?to?tall? fescue?plots,?volatilization?was?not?a?major?pathway?for?N?loss?(Marshall?et?al,?1998).??Studies? with?slow?release?fertilizers?showed?less?than?2%?N?loss?through?volatilization?(Knight?et?al.,? 2007;?Torello?et?al.,?1983;?Nelson?et?al.,?1980).??Fertilizer?applications?to?bentgrass?(Agrostis? stolonifera)?had?volatile?N?loss?in?the?descending?order:?urea,?sulfur?coated?urea,?methylene? urea,?composted?sewage?sludge,?NH 4 NO 3 ,?and?polymer?coated?urea?(Knight?et?al.,?2007).?? Nitrate,?an?anion,?is?highly?mobile?in?the?soil?and?may?be?lost?via?leaching,?denitrification,? and?plant?uptake?(Johnson?et?al.,?2006;?Civeira?and?Lavado,?2007).??Factors?affecting?the? concentration?and?rate?of?leaching?include?soil?type,?irrigation?rate,?N?application?rate,? frequency?and?timing?of?fertilizer?applications,?stand?density,?rooting?characteristics,?and?plant?N? demands?(Petrovic,?1990).??Nitrate?leaching?may?also?differ?from?season?to?season,?with?fall? applications?having?a?lower?rate?of?loss?(Burger?and?Venterea,?2008).???Up?to?one?half?to?two? thirds?of?applied?N?may?leach?in?the?first?14?days?after?fertilizer?application?(Pare?et?al.,?2008).?? Nitrates?leached?from?fertilizer?applications?have?the?potential?to?negatively?affect?water?quality? and?subsequently?cause?human?health?concerns,?especially?with?pregnant?women?and?nursing? infants?(Pare?et?al.,?2008).??? Nitrate?loss?may?be?controlled?through?management?practices.??Snyder?et?al.?(1984)? looked?at?the?potential?of?tension?meter?controlled?irrigation?systems?to?reduce?N?leaching.?? Ammonium?nitrate?and?sulfur?coated?urea?were?applied?at?a?5?g?N?m ?2 ?month ?1 .??Nitrogen?loss? ranged?from?22?to?56%?from?the?daily?irrigated?NH 4 NO 3 ?plots?(no?sensors)?and?from?<1?to?6%? 12? ? from?all?sensor?irrigated?plots.??The?study?concluded?that?sensor?irrigation?significantly?reduced? N?leaching?from?all?N?sources.??? Some?studies?have?shown?that?NO 3 ?leaching?may?also?be?reduced?through?plant?cultivar? selection.??One?study?looked?at?a?St.?Augustine?(Stenotaphrum?secumdatum)?lawn?versus?a? mixed?medium?landscape?(12?ornamental?species)?and?found?total?N?leaching?losses?of?4.1?and? 48.3?kg?N?ha ?1 ?in?one?year,?respectively?(Erickson?et?al.,?2001).??Bowman?et?al.?(2002)?found? similar?results?amongst?6?different?turf?species,?with?St.?Augustine?being?the?most?effective?and? Meyer?zoysiagrass?(Zoysia?japonica)?the?least?effective.??Studies?have?also?concluded?that?NO 3 ? leaching?is?more?prevalent?on?sandy?soils?(Brown?et?al.,?1982;?Bigelow?et?al.,?2001;?Bowman?et? al.,?1998;?Rieke?and?Ellis,?1972;?Starr?and?DeRoo,?1981).?Nitrate?leaching?may?also?be?reduced?in? dense?or?deep?rooted?turf?species?(Pare?et?al.,?2006;?Bowman?et?al.,?1998).? ?Due?to?the?expense?that?homeowners?and?turfgrass?managers?incur?with?inorganic? fertilizers,?alternative?fertilizer?sources?have?been?studied.??Guillard?and?Kopp?(2004)?looked?at? the?potential?of?organic?N?sources?on?cool?season?grasses.??Two?treatments,?polymer?coated? sulfur?coated?urea?(synthetic?organic)?and?Sustane??(organic?slow?release),?showed?significantly? less?NO 3 ?loss?through?leaching,?compared?to?NH 4 NO 3 .??Spanning?the?entire?three?year?study,?a? total?of?441?kg?N?ha ?1 ?was?applied?for?each?treatment,?and?total?NO 3 ?leaching?loss?was?16.8,?1.7,? and?0.6%?of?total?applied?N?for?NH 4 NO 3 ,?polymer?coated?sulfur?coated?urea,?and?Sustane?,? respectively.??? King?and?Torbert?(2007)?observed?NO 3 ?losses?from?NH 4 NO 3 ,?sulfur?coated?urea,? composted?dairy?manure,?and?poultry?litter?applied?on?bermudagrass.??They?found?that?over?a? 10?week?period?NH 4 NO 3 ,?sulfur?coated?urea,?composted?dairy?manure,?and?poultry?litter?treated? 13? ? plots?lost?37,?25,?10,?and?7%?of?total?N?applied,?respectively.??Brown?et?al.?(1982)?found?similar? results?among?NH 4 NO 3 ,?12?12?12?(12%?ammoniacal?N),?Milorganite,?isobutylene?diurea,?and? urea?formaldehyde?fertilized?plots,?with?the?largest?N?loss?from?turf?fertilized?with?NH 4 NO 3 ,?and? decreasing?in?order?as?listed.??The?largest?NO 3 ?loss?was?23%,?and?there?was?a?25?to?30?day?delay? before?NO 3 ?appeared?in?leachate?from?the?Milorganite?source.??They?concluded?that?applications? of?slow?release?N?sources?would?provide?minimum?NO 3 ?loss,?while?offering?a?continuous?N? supply.? Nitrate?can?also?be?denitrified,?a?microbial?process?converting?NO 3 ?or?nitrous?dioxide ? to? N?gas?or?nitrous?oxide,?with?subsequent?loss?to?the?atmosphere?(Parsons?et?al.,?1991;? Mahimairaja?et?al.,?1995).?Factors?promoting?the?rate?of?denitrification?include:?1)?high?irrigation? frequency?(Christensen,?1983),?2)?high?rate?of?N?fertilization?(Mahimairaja,?1995;?Williams?et?al,? 1992;?Webster?and?Dowdell,?1982),?3)?addition?of?organic?matter?(Christensen,?1983;?Mancino? and?Torello,?1986),?4)?saturated?or?high?soil?water?content?(Mancino?et?al.,?1988;?Petrovic,?1990),? and,?5)?warm?soil?temperatures?(Mancino?et?al.,?1988;?Bijoor?et?al.,?2008).??Highest?NO X ?(mono?N? oxides)?emissions?occur?directly?after?N?addition?(Thornton?et?al.,?1998).??These?gaseous?forms?of? N?are?lost?more?rapidly?in?finer?textured?soils?(Gentile?et?al.,?2008;?Mancino?et?al.,?1988).?? Mancino?et?al.?(1988)?found?denitrification?N?loss?rates?from?potassium?nitrate?to?be?2.2?and? 5.4%?of?applied?N.??Soil?temperatures?of?30?C?and?saturated?soils?significantly?increased?N?loss?to? between?44.6?and?92.6%?of?applied?N?(Mancino?et?al.,?1988).??When?soils?were?not?saturated,? NO?and?NO 2 ?emissions?were?below?1%?(Mancino?et?al.,?1998).? Nitrate?may?also?be?immobilized?and?rendered?unavailable?to?plants?in?the?soil?by? reverting?to?organic?N?through?microbial?processes,?and?it?will?no?longer?be?plant?available.?? Factors?that?affect?immobilization?include:?1)?organic?matter?content,?2)?C:N?ratio,?and,?3)?soil? 14? ? microbial?biomass?(Hadas?et?al.,?1992).??A?microbial?efficiency?factor?of?0.4?and?a?C:N?ratio?of? 19:1?or?higher?are?required?for?immobilization?to?occur?(Hadas?et?al.,?1992;?Calderon?et?al.,? 2004).??A?study?looking?at?hog?manure?and?liquid?dairy?manure?found?N?immobilization?to?be?14? and?40%?of?initial?NH 4 ?applied,?respectively?(Burger?and?Venterea,?2008).??? Turfgrass?and?Nitrogen? There?is?an?abundance?of?research?on?waste?products?and?their?beneficial?properties?on? conventional?row?crops;?however,?research?in?organic?fertilization?in?turfgrass?systems?is?lacking.?? Turfgrasses?are?the?most?crucial?component?of?athletic?fields,?golf?courses,?and?homeowner? lawns?(Beard,?1973).??In?the?southeast?U.S.,?the?warm?humid?environment?requires?the?use?of? mostly?warm?season?turfgrasses,?such?as?bermudagrass,?zoysiagrass?,?centipedegrass? (Eremochloa?ophiuroides),?and?St.?Augustinegrass.??Warm?season?turfgrasses?assimilate?CO 2 ?via? the?C 4 ?(four?C?atom?in?C?fixation?process?during?photosynthesis)?pathway,?with?optimized?growth? between?27?and?35?C?and?dormancy?in?temperatures?lower?than?10?C?(McCarty,?2001).?? ? Bermudagrass?is?a?suitable?selection?for?establishment?in?the?Southeast?because?of?its? vigorous?growth,?and?for?golf?course?and?athletic?fields?this?is?an?important?property?(Guertal? and?Hicks,?2009).??Nitrogen?is?an?essential?element?for?turf?establishment,?and?finding?an? appropriate?rate?can?be?challenging.??Nitrogen?plays?an?important?role?in?turf?color,?growth,? shoot?rhizome?and?stolon?densities,?wear?tolerance,?and?recovery?(Carrow?et?al.,?1987).?? Turfgrass?managers?will?often?apply?excessive?amounts?of?N?in?order?to?overcome?stress?and? injury?wear,?but?this?practice?can?not?only?cause?negative?effects?to?the?turf,?but?also?negative? environmental?effects?(Guertal?and?Evans,?2006).??Over?fertilizing?turf?with?N?can?cause? problems?such?as?increased?mowing?frequency,?decreased?recovery,?decreased?rhizomes?and? 15? ? stolons,?and?decreased?disease?tolerance?(Ramos?and?Curbelo,?1978;?Goatley?et?al.,?1994;? Mitchell?and?Dickens,?1979;?Golembiewski?and?Danneberger,?1998).? ?Tifsport??bermudagrass?was?released?from?the?University?of?Georgia?Coastal?Plain? Experimental?Station?in?1997?and?is?rapidly?becoming?the?most?popular?turf?species?for?southern? golf?courses?and?athletic?fields?(Hanna?et?al.,?1997).???Tifsport??is?a?good?fit?for?Alabama?turf? systems?because?of?its?cold?tolerance,?reduced?genetic?variability,?and?ability?to?recover?from? stress?and?injury?(Hanna?et?al.,?1997;?Trenholm?and?Unruh,?2005;?Karcher?et?al.,?2005).?? Bermudagrass?is?also?beneficial?because?of?its?rapid?establishment?via?lateral?stems? (rhizomes/stolons)?makes?it?competitive?against?weeds?and?disease?(Guertal?and?Evans,?2006;? Patton?et?al.,?2004.)? Typical?fertilizer?programs?for?bermudagrass?fairways?require?about?20?to?40?kg?N?ha ?1 ? growing?month ?1 ?(Wu?et?al.,?2007).?This?is?done?to?prevent?loss?of?N?through?NO 3 ?leaching,?NH 3 ? volatilization,?and?other?gaseous?losses.??Fertilizer?N?loss?can?be?high?and?is?a?function?of? management,?such?as?irrigation,?N?source,?rate,?and?timing?(Pare?et?al.,?2008).??Organic?products? may?have?a?role?here,?because?of?their?slow?release?properties.? ? Cool?season?grasses?such?as?bentgrass,?fine?fescue,?tall?fescue,?and?bluegrass?(Poa?spp.)? have?optimal?growth?between?16?and?24?C?(Jiang?and?Huang,?2000).??Cool?season?grasses?have? only?limited?adaptation?in?the?South?and?perform?the?best?in?the?spring?and?fall.??Bentgrass?is? used?only?for?putting?greens,?even?though?the?heat?of?the?summer?months?will?decrease?root? and?shoot?growth?(Guertal?et?al.,?2005).??In?order?to?maintain?a?green?color?on?golf?course?greens? and?a?smooth?putting?surface?during?the?winter?months,?bentgrass?is?a?common?selection,?but? management?practices?must?be?adapted?to?increase?its?survivability?during?the?summer?(Guertal? 16? ? et?al.?2005).??The?main?reason?for?decreased?root?density?is?due?to?canopy?heat,?which?can?be? reduced?by?syringing?and/or?the?use?of?fans?to?circulate?the?air?over?the?green?(Guertal?et?al.,? 2005).? ? Koeritz?and?Stier?(2009)?showed?that?an?application?of?146?kg?N?ha ?1 ?yr ?1 ?produced?best? turf?quality,?spring?green?up,?and?highest?shoot?density?for?cool?season?putting?greens.??Creeping? bentgrass?requires?intensive?maintenance?due?to?its?disease?susceptibility?to?dollar?spot? (Sclertonia?homeocarpa?F.T?Bennett),?brown?patch?(Rhizoctonia?solani?Kuhn),?pink?snow?mold? [Microdochium?nivale?(Fries)?Samuels?and?Hallett],?and?gray?snow?mold?(Typhula?spp.)??(Warnke,? 2003).? Common?Nitrogen?Fertilizer?Sources? There?are?many?available?N?sources?that?will?sufficiently?supply?nutrients?to?turfgrass.?? These?are?often?classified?as?inorganic?soluble,?synthetic?organic?soluble,?synthetic?organic?slow? release,?and?natural?organic?slow?release.??The?most?commonly?used?are?inorganic?soluble? fertilizers.?These?generally?release?nutrients?for?immediate?plant?utilization,?but?nutrients?are? vulnerable?to?environmental?loss.??These?products?have?proven?effective,?but?Landschoot?and? Waddington?(1987)?showed?that?more?frequent?applications?are?needed?to?obtain?the? uniformity?of?turfgrass?quality?that?organics?offer.??Examples?of?inorganic?soluble?fertilizers?are? NH 4 NO 3 ?and?(NH 4 ) 2 SO 4 .??These?fertilizers?are?often?used?when?large?amounts?of?N?need?to?be? added?to?the?soil,?and?they?are?plant?available?immediately?after?application.??Ammonium?sulfate? can?be?used?to?lower?soil?pH.? The?only?soluble?synthetic?organic?fertilizer,?urea,?is?often?used?in?turfgrass?fertilization.?? Urea?is?organic?because?it?contains?C,?but?it?is?not?commonly?applied?as?a??true?organic??fertilizer? 17? ? because?it?is?manufactured?synthetically.??Urea?offers?a?high?nutrient?analysis?(46?0?0)?and?a? rapid?turf?response?that?produces?similar?yields?and?color?response?to?that?of?NH 4 NO 3 ? (Landschoot?and?Waddington,?1987;?Carrow,?1997).??? Synthetic?organic?slow?release?products?are?classified?as?a?physical?or?chemical?slow? release.??Physical?slow?release?fertilizers?contain?resin?coats?or?sulfur?coats?that?degrade,? releasing?nutrients?as?a?function?of?coat?integrity?(Peacock?and?DiPaola,?1992).??The?release?rate? varies?with?the?thickness?and?degradation?properties?of?the?resin?coat?(Hummel,?1989).?? Nutrients?are?released?when?water?moves?by?osmosis?through?the?resin?coat,?and?urea?solution? diffuses?back?out?(Hummel,?1989).??Besemer?(1963)?reported?that?bentgrass?fertilized?every?13? to?17?weeks?with?sulfur?coated?urea?offered?similar?turf?quality?to?that?of?a?monthly?application? of?soluble?fertilizers.??Hummel?and?Waddington?(1984)?found?sulfur?coated?urea?pellets?3?years? after?application,?which?contained?up?to?26%?of?applied?N.??Coated?slow?release?products?have? shown?reduced?NO 3 ?leaching?losses?when?compared?to?soluble?fertilizers?(Guillard?and?Kopp,? 2004).??Hummel?(1989)?found?the?highest?N?recoveries?with?sulfur?coated?urea?and?resin?coated? urea?when?compared?to?standard?soluble?urea?and?concluded?that?resin?coated?ureas?were?an? excellent?choice?for?N?supply.??? Synthetic?chemical?slow?release?products,?such?as?IBDU?(isobutylenediurea)?and? methylene?urea,?release?N?by?hydrolysis?and?microbial?activity.??Short?chain?methylene?ureas?can? provide?a?rapid?initial?color?response,?but?this?varies?with?source?(Carrow,?1997).??Slow?release? products?offer?a?low?risk?for?crop?burn,?fewer?applications?at?higher?rates?with?longer?duration,? and?less?risk?of?N?loss?to?volatilization?and?leaching?(Hummel?and?Waddington,?1981).??Slow? release?N?sources?also?come?in?several?particle?sizes?and?wide?variations?of?long?term?N?release,? offering?more?choices?to?match?the?proper?application?(Carrow,?1997).? 18? ? Natural?organics,?otherwise?known?as?slow?release?N?fertilizers?(SRN),?contain?C,?but?are? derived?from?waste?products?(Christians,?2004).?Natural?slow?release?organics?are?finding?new? popularity?with?fertilizer?companies?because?they?have?been?shown?to?provide?substantial?plant? available?N,?as?well?as?a?source?of?micronutrients?(Eldridge?et?al.,?2008).??Besides?offering?a?slow? release?quality,?there?are?numerous?sources?of?waste?by?products?to?be?reused.??Natural?organic? slow?release?N?products?release?nutrients?more?quickly?as?particle?size?decreases?(Hummel?and? Waddington,?1981).??Slow?release?N?products?also?have?lower?tissue?burn?potentials,?so?fewer? applications?at?higher?rates?can?be?made,?while?providing?a?longer?duration?of?N?release? (Hummel?and?Waddington,?1981).??The?inconsistency?of?N?release?from?slow?release?N?products? presents?the?need?to?study?individual?products?to?determine?accurate?fertilizer? recommendations?(Hummel?and?Waddington,?1981).? Organic?Nitrogen?in?Turf? Organic?wastes?have?demonstrated?their?ability?to?provide?nutrients?to?plants?at?rates? sufficient?for?quality?growth?(Mamo?et?al.,?1999).??Research?is?limited?on?the?efficacy?of?organic? sources?in?turfgrass?systems,?but?some?research?shows?that?organics?have?potential?in?turfgrass? fertilizer?programs.??The?release?pattern?of?organic?products?is?inconsistent?and?each?individual? product?must?be?evaluated?so?that?accurate?recommendations?for?fertilizer?programs?may?be? made?(Carrow,?1997).? The?slow?release?property?that?organic?products?offer?may?help?reduce?fertilizer?N?loss? and?may?help?reduce?the?factors?(e.g.,?irrigation?schedule,?N?source,?rate?and?timing?of? application)?that?effect?N?loss?(Kerek?et?al.,?2003).??Nitrates?are?often?leaches?from?the?soil,? especially?in?sandy?golf?course?greens?(Mazur?and?White,?1983).??One?study?has?shown?that?plots? 19? ? fertilized?with?organics?only?contained?0.6?and?1.7%?NO 3 ?N?of?N?applied,?while?applications?of? NH 4 NO 3 ?had?16.8%?NO 3 ?in?the?leachate?(Guillard?and?Kopp,?2004).??? A?University?of?Florida?study?on?St.?Augustine?grass?showed?equal?or?greater?response? from?Milorganite?and?Scotts?Turf?Builder?treatments?(The?Scotts?Company,?LLC.,?Marysville,?OH)? when?compared?to?other?commercially?available?inorganic?products?(Cisar,?2004).??Many?organic? products?have?proven?to?be?a?legitimate?selection?for?turf?fertilization,?but?there?is?some? research?that?shows?organics?have?limited?turf?response,?and?results?show?high?variability?within? sources?(Carrow,?1997;?Peacock?and?Daniel,?1992).??Landschoot?and?Waddington?(1987)? examined?organic?fertilizer?application?on?bluegrass?and?found?that?turf?response?varied?widely? with?source.? Some?organic?N?fertilizers?have?been?shown?to?have?disease?suppressing?traits?allowing? turf?to?outgrow?disease?problems?(King?and?Torbert,?2007).??Organics?have?been?shown?to? reduce?dollar?spot?severity?as?compared?to?the?control?(Davis?and?Dernoeden,?2002),?and?they? also?reduced?necrotic?ring?spot?(Guillard?and?Kopp,?2004;?Melvin?and?Vargas,?1994).?Organic? products?contain?C?compounds,?which?increased?soil?bacterial?populations?within?four?days?after? treatment?(Li,?2005).??A?study?of?bentgrass?showed?increased?populations?and?increased? microbial?activity?in?plots?treated?with?compost?and?sludge?(Tian?et?al.,?2008).??? Study?Objectives? ? The?objectives?of?this?research?were?to:??1)?evaluate?turfgrass?response?to?organic? fertilizers?in?the?field?by?measuring?turf?color,?quality,?clipping?yield,?N?uptake,?and?soil?NO 3 ?N? and?NH 4 ?N,?and?2)?measure?N?mineralization?from?organic?fertilizers?as?affected?by?soil? temperature?in?the?laboratory. 20? ? Materials?and?Methods? Field?Study? In?2009?and?2010,?field?studies?were?conducted?at?the?Auburn?University?Turfgrass? Research?Unit?(TGRU)?located?on?the?Auburn?University?campus.??Studies?were?initiated?on?27? Apr.?2009?and?4?May?2010.??The?experiments?were?conducted?on?Tifsport?and?Tifway?hybrid? bermudagrass?(Cynodon?dactylon?L.???Cynodon?transvaalensis?Burtt?Davy)?fairways,?respectively.?? Both?studies?were?conducted?on?a?Marvyn?loamy?sand?(Fine?loamy,?siliceous,?thermic?Typic? Paleudult)?soil?type.??Initial?soil?tests?for?each?experiment?are?listed?in?Table?1.??There?were?no?N? fertilizers?applied?to?the?field?studies?for?one?year?prior?to?the?application?of?treatments?used?for? this?study.??Fungicide?and?pesticide?treatments?were?used?as?needed?and?followed? recommended?guidelines.??Table?2?includes?dates,?rates,?and?products?used?for?each?individual? study.?? The?fertilizer?treatments?listed?in?Tables?3?and?4?were?used?in?each?study,?plus?one? unfertilized?control.??The?ten?treatments?were?replicated?four?times?in?a?randomized?complete? block?design.??Each?study?was?mown?prior?to?fertilizer?application.??Treatments?were?hand? applied?to?1.2?x?2.4?m?plots?at?4.9?g?N?m ?2 ?and?irrigated?directly?after?application.??? The?two?studies?were?mown?once?per?week?at?a?height?of?1.9?cm?with?a?Tru?Cut?H?2C? reel?mower?(Advanced?Mower,?Bessemer,?AL.)?and?clippings?were?removed?for?analysis.??Each? plot?was?irrigated?with?2.54?cm?water?week ?1 ?in?the?absence?of?rainfall.??Data?collected?from?both? experiments?included?clipping?yield,?fertilizer?pickup,?shoot?density,?rhizome/stolon?density,?root? density,?visual?color?ratings,?colorimeter?measurements,?soil?total?and?extractable?N,?and?an?end? of?studyl?soil?microbial?biomass?extraction.??Turfgrass?color?response?was?measured?weekly?via? 21? ? qualitative?visual?color?ratings.??The?scale?was?from?one?to?nine,?with?one?being?brown?turf?and? nine?being?an?optimal?dark?green?color.??? Weekly?colorimeter?measurements?were?also?taken?with?a?Fieldscout?CM?1000? chlorophyll?meter?(Spectrum?Technologies,?Inc.,?Plainfield,?IL.).??The?colorimeter?is?a?remote? sensing?device?that?directs?a?band?of?light?onto?the?turf?surface,?and?a?meter?collects?reflectance? data.?The?reflectance?data?is?thought?to?correlate?to?turf?chlorophyll?content?and?hence? greenness.?Widely?marketed?in?the?turf?industry,?the?device?lacks?calibration?data,?and?this?was? one?reason?for?inclusion?in?our?study.??In?every?case,?five?colorimeter?measurements?were?taken? from?each?plot,?and?results?were?averaged.??Measurements?were?recorded?with?the?colorimeter? hand?held?at?a?1?m?height?between?1000?and?1400?hours?on?cloudless?days.? Clippings?were?harvested?from?each?individual?plot?once?per?week,?using?the?same? mower?as?used?for?plot?maintenance,?and?immediately?sieved?through?a?2?mm?mesh?screen,?in? order?to?separate?any?fertilizer?picked?up?by?the?mower.??Any?collected?fertilizer?was?weighed? and?reapplied?to?the?plot.??Fertilizer?loss?was?minimal?two?weeks?after?application,?so?samples? were?no?longer?sieved?for?fertilizer?removal.??Harvested?clippings?were?forced?air?dried?at?70?C? for?48?hours?and?weighed?for?total?clipping?dry?matter?yield.??Clippings?were?analyzed?via?dry? combustion?for?total?N?using?a?LECO?TruSpec?CN?(LECO?Corp.,?St.?Joseph,?MI.).??? Soil?and?thatch?temperatures,?at?2.54?and?1?cm?under?the?turfgrass?surface,?respectively,? were?monitored?every?ten?minutes?using?a?HOBO?Pro?Series?datalogger?(Onset?Computer?Corp.,? Bourne,?MA).??Three?soil?samples?were?taken?from?each?plot?weekly?to?a?7.62?cm?depth?below? the?thatch?layer?with?a?0.95?cm?diameter?probe.??Samples?were?combined?and?sieved?through?a? 2?mm?screen.??Soil?samples?were?extracted?with?2?M?KCl?and?analyzed?for?NH 4 ?N?and?NO 3 ?N? concentration?colorimetrically?(Sims?et?al.,?1995)?using?a?BioTek?uQuant?Microplate? 22? ? Spectrophotometer?(Winooski,?VT).??Total?N?and?C?in?the?soil?were?determined?by?a?dry? combustion?LECO?TruSpec?CN?(Mulvaney?et.?al.,?2008b).? Shoot,?rhizome/stolon,?and?root?densities?were?taken?on?28?July?2009?and?on?1?June,?7? July,?and?27?July?2010.??All?densities?were?measured?by?taking?two?cores?(6?cm?diameter?and?6.35? cm?deep)?with?a?tubular?turf?plugger?(Turf?Tec?International,?Tallahassee,?Fl.).??Shoots?were? counted?by?hand,?and?rhizome/stolons?and?roots?were?cleaned?of?soil,?forced?air?dried?at?70?C? for?48?hours,?and?weighed.??When?each?study?was?complete,?a?final?measurement?of?soil? microbial?biomass?was?collected?using?the?method?described?by?Parkinson?and?Paul?(1982).?? Samples?were?brought?to?field?capacity?and?fumigated?with?ethanol?free?chloroform?and?then? incubated?for?24?hours.??The?CO 2 ?evolved?was?then?collected?with?1?M?NaOH.??Samples?were? incubated?for?10?days?in?the?dark.??The?CO 2 ?evolution?was?calculated?by?titration?of?the?NaOH? solution?with?1.5?M?BaCl 2 ?and?0.25?M?HCl.??? Laboratory?Incubation?Study? ? Laboratory?incubation?studies?to?evaluate?N?mineralization?were?carried?out?in?2009?and? 2010.??Treatments?were?soil?temperatures?(15,?25,?and?35?C)?in?combination?with?nine?fertilizer? treatments?shown?in?Table?1.?An?unfertilized?control?was?also?included.??Each?experiment?was? arranged?in?a?completely?random?design?with?four?replications?of?each?treatment.??Each?entire? experiment?was?repeated?in?time.?Thus,?there?were?six?12?week?experiments?in?total,?beginning? on?20?Jan.?2009?(25?C),?14?Apr.?2009?(25?C),?11?Aug.?2009?(15?C),?15?Dec.?2009?(35?C),?12?Jan.? 2010?(15?C),?and?6?Apr.?2010?(35?C).? ? Each?25?and?35?C?experiment?was?conducted?in?a?0.7?m 3 ?laboratory?incubator?(Isotemp,? Fisher?Scientific,?Pittsburgh,?PA).??The?15?C?experiments?were?conducted?in?an?isolated?seed? 23? ? refrigerator?room.??Microlysimeters?(described?below)?were?removed?weekly?for?sample? collection,?and?the?experimental?units?were?re?randomized?each?week?within?the?chamber.??Air? temperatures?were?monitored?throughout?each?study?via?a?Hobo?temperature?sensor.? ? A?Marvyn?loamy?sand?(Fine?loamy,?siliceous,?thermic?Typic?Paleudult)?was?used?in?each? experiment.??The?soil?was?collected?from?the?top?7.6?cm?of?the?Auburn?University??Old?Rotation?.?? Initial?N?and?C?values?were?0.62?and?9.2?g?kg ?1 ,?respectively.??Falcon?filter?microlysimeters?were? assembled?with?fiberglass?filters?(Becton?Dickinson,?Franklin?Lakes,?NJ;?Nadelhoffer,?1990).??The? soil?was?brought?to?field?capacity?(13.4%?w/w),?and?a?13.8?g?N?m 2 ?rate?of?the?treatments?listed?in? Table?1?were?added?to?50?g?dry?weight?soil.??The?soil?and?fertilizer?were?thoroughly?mixed,?and? then?placed?into?the?microlysimeter.??Each?microlysimeter?was?extracted?with?0.01M?CaCl 2 ?on? days?0,?1,?3,?5,?and?7?after?application?and?then?once?per?week?for?10?weeks?after?the?first?week.??? To?extract?NH 4 ?N?and?NO 3 ?N?in?soil?solution,?the?microlysimeters?were?filled?with?100?mL? 0.01?M?CaCl 2 ?and?allowed?to?equilibrate?for?one?hour?(Nadelhoffer,?1990).??The?soil?solution?was? then?extracted,?the?volume?of?extract?was?measured,?and?a?sub?sample?taken.??The?sub?sample? was?analyzed?for?NH 4 ?N?and?NO 3 ?N?colorimetrically?using?a?spectrophotometer?(Sims?et?al.,? 1995).??After?each?extraction,?the?microlysimeters?were?returned?to?the?incubation?chamber?and? allowed?to?aerobically?incubate?until?the?next?extraction.??Soil?pH?was?taken?at?the?end?of?each? experiment.? 24? ? Results?and?Discussion? Field?Study?? Fertilizer?Removal? ? In?2009,?fertilizer?removal?was?not?measured.??In?2010,?fertilizer?removal?was?included?in? the?study,?with?all?collected?fertilizer?returned?to?the?plot?after?measurement.??There?was? significant?fertilizer?removal?with?the?harvested?clippings?at?one,?and?in?some?cases,?two?weeks? after?fertilization?(Table?5).??Bermudagrass?fertilized?with?Sustane??(4?6?4)?had?greatest?fertilizer? removal,?more?than?twice?as?much?as?any?other?treatment.??Virtually?no?fertilizer?was?removed? from?the?urea,?Milorganite?,?Scotts?Turf?Builder,?or?the?TOP?(fine?grade)?fertilized?plots.??The?two? treatments?with?greatest?fertilizer?loss?in?week?1?still?had?measureable?fertilizer?loss?in?week?2? (Sustane??4?6?4?and?Sustane??8?2?4).? ? On?a?creeping?bentgrass?(Agrostis?palustris?Huds.)?putting?green,?greatest?loss?of? fertilizer?due?to?clipping?harvest?was?found?from?an?IBDU?source,?followed?by?Polyon?,?and?then? Milorganite?(Landschoot?and?Mancino,?2000).??The?authors?noted?that?differences?in?fertilizer? removal?were?due?to?solubility,?size?and?density?of?the?materials.??In?our?study,?both?solubility? and?size?affected?removal,?as?no?fertilizer?was?harvested?from?the?soluble?urea?plots,?while?the? treatment?with?greatest?removal?(Sustane??4?6?4)?was?both?a?slow?release?and?large?product,? with?the?largest?SGN?(average?particle?size?diameter?multiplied?by?100)?(Table?1).? ? 25? ? Turf?Color?Response? In?both?years?the?bermudagrass?responded?quickly?to?applications?of?urea,?with? significant?greenup?in?both?visual?color?(Tables?6?and?7;?Figures?1?and?2)?and?chlorophyll?meter? readings?(Tables?8?and?9;?Figures?3?and?4)?within?5?days.??In?2010,?plots?fertilized?with?Scotts?Turf? Builder??also?showed?a?more?rapid?greenup?than?all?other?treatments.??This?treatment?was?not? included?in?the?2009?study.?Rapid?greenup?from?the?TurfBuilder?would?be?expected,?as?the? majority?of?that?products??N?is?soluble?urea?and?only?0.9%?is?slow?release?(methylene?urea).?? Application?of?NatureSafe?Starter?produced?a?significantly?greener?turf?(as?compared?to?the? control)?within?two?weeks?after?application?(2009?and?2010).??Application?of?any?fertilizer? produced?greener?turf?than?observed?in?the?control?by?week?4?in?2009?and?by?week?3?in?2010.?? Urea?and?NatureSafe?Starter?consistently?produced?the?greenest?turf?after?week?4?in?2009.??In? 2009,?application?of?any?N?source?produced?greener?turf?(compared?to?the?control)?at?28?days? after?treatment?(DAT).??In?2010,?the?application?of?any?N?source?created?greener?turf?at?21?DAT.??? Application?of?urea,?NatureSafe?Starter,?NatureSafe?StressGuard,?Sustane??(8?2?4),?and? Scotts?Turf?Builder?consistently?produced?the?highest?visual?color?ratings?after?week?4?in?2010.?? Application?of?Top?(fine?and?regular)?and?Sustane??(4?6?4)?often?produced?higher?color?ratings? than?observed?in?the?control?plots,?but?differences?within?these?sources?were?not?observed?at?4,? 5,?and?6?weeks?after?application.??Any?difference?in?visual?color?due?to?fertilization?was?largely? gone?by?week?10?in?2009?and?week?9?in?2010.??In?both?years?there?was?never?a?slow?release? organic?product?that?provided?any?longer?color?response?than?that?observed?in?bermudagrass? fertilized?with?urea.? 26? ? Chlorophyll?meter?readings?for?Sustane??(4?6?4)?or?Top?(fine?grade)?were?not?statistically? different?from?those?measured?in?the?control?for?the?entirety?of?the?2009?study?(Table?8).?? Chlorophyll?meter?readings?for?urea,?Milorganite,?NatureSafe?Starter,?and?Top?(regular?grade)? were?all?significantly?higher?than?those?measured?in?the?control?for?the?entire?twelve?week?study? (2009).??NatureSafe?StressGuard?also?had?higher?ratings?than?observed?in?the?control?plots?for?all? measurement?dates,?except?for?the?first?two?weeks.??As?with?the?relative?visual?color?ratings,? application?of?urea?produced?higher?chlorophyll?meter?readings?that?were?as?long?lived?as?those? measured?in?plots?fertilized?with?slow?release?sources.??For?example,?at?12?week?after? application?(2009)?plots?fertilized?with?urea,?Milorganite,?NatureSafe?Starter,?NatureSafe? StressGuard?and?Top?(regular?grade)?all?had?similarly?high?chlorophyll?meter?readings,?which? were?greater?than?measured?in?the?unfertilized?plots?(Table?8).? In?2010,?the?chlorophyll?meter?readings?for?plots?fertilized?with?urea,?Scotts?Turf?Builder,? NatureSafe?Starter,?and?NatureSafe?StressGuard?were?significantly?higher?than?those?measured? in?the?control?plots?through?week?8.??Data?collected?from?the?Top?(fine?and?regular?grade)? treated?plots?was?generally?higher,?but?not?significantly?different?than?that?measured?in?the? control?(Table?9).??Plots?fertilized?with?the?Sustane??products?had?a?similar?response?as?Top? fertilized?plots,?except?that?there?was?an?extended?greening?response?to?the?Sustane??products,? with?greener?turf?(as?compared?to?the?control)?in?weeks?6,?7,?and?8?of?the?study.??There?were?no? significant?differences?in?chlorophyll?meter?readings?amongst?treatments?after?week?8?(2010)? (Table?9).? Although?hand?held?chlorophyll?meters?have?become?a?commonly?used?research?tool,? there?is?little?data?which?examines?their?correlation?with?commonly?used?indices?such?as?turf? color.??Figures?5?and?6?show?correlations?between?visual?turf?color?and?chlorophyll?meter? 27? ? readings,?for?all?data?collected?in?each?study?period.??Correlations?in?2009?were?stronger?with?an? R 2 ?of?0.81,?while?in?2010?there?was?a?weaker?relationship,?with?an?R 2 ?of?0.43.??Visual?ratings? sometimes?detected?differences?for?a?greater?period?of?time,?with?significant?differences?in?color? lasting?for?84?and?77?days?after?application?in?2009?and?2010,?respectively.??In?these?same?years? significant?differences?in?chlorophyll?meter?reading?were?observed?for?the?entire?84?day?period? in?2009,?but?differences?were?gone?by?56?days?after?application?in?2010?(Table?9).? ? A?recent?paper?which?examined?relationships?between?normalized?difference?vegetation? index?(NDVI)?and?visual?quality?found?different?relationships?due?to?turf?species?and?mowing? height?(Lee?et?al.,?2011).??They?found?a?lack?of?precision?in?the?ability?of?NDVI?to?predict?visual? quality?and?recommended?that?data?be?compared?within?the?same?species?and?mowing?height.?? By?comparisons,?others?found?significant?correlations?between?hand?held?reflectance?meters? and?turfgrass?chlorophyll?and?concluded?that?hand?held?meters?could?be?a?useful?tool?for?N? management?(Mangiafico?and?Guillard,?2005).? Clipping?Yield?and?Tissue?Nitrogen? ? At?two?weeks?after?application,?plots?treated?with?urea?had?significantly?greater?clipping? yield?any?other?treatment?(2009)?(Table?10).??Differences?were?less?distinct?in?2010,?with?urea? and?Scotts?Turf?Builder?plots?both?having?greatest?yield?at?3?weeks?after?application?(Table?11).?? Plots?fertilized?with?organic?products?often?produced?a?lower?clipping?yield,?and?in?many?cases? yield?did?not?differ?from?that?measured?in?the?unfertilized?plots.??For?example,?in?2009?plots?that? were?fertilized?with?organic?N?products?produced?no?significant?increase?in?clipping?yield?(as? compared?to?the?control)?at?weeks?3?through?8.??The?only?exception?to?this?was?the?organic? 28? ? product?NatureSafe?Starter,?which?did?produce?more?clippings?than?measured?in?the?control? (Table?10).??? ? In?2009,?as?with?clipping?yield,?tissue?N?significantly?increased?in?bermudagrass?fertilized? with?urea?(Table?12).??Fertilization?with?the?N?source?NatureSafe?Starter?also?often?increased? tissue?N?above?that?measured?in?the?control,?with?a?significant?increase?in?tissue?N?(above?the? control)?at?weeks?1?through?5?after?application.??By?9?weeks?after?application?there?were?few? differences?in?tissue?N?as?affected?by?N?source?(Table?12).? ? In?2010?application?of?urea?or?Scotts?Turf?Builder?increased?tissue?N?the?most,?followed? by?application?of?NatureSafe?Starter?(Table?13).??These?treatments?had?greater?leaf?N?for?the?first? 5?weeks?after?application.??In?both?2009?and?2010,?the?organic?product?NatureSafe?StressGuard? increased?leaf?N?(as?compared?to?the?control)?in?later?weeks?of?the?study,?with?significantly?more? tissue?N?at?weeks?3?through?5?in?2009?and?weeks?4?and?5?in?2010?(Tables?12?and?13).?In?2010,?by? 7?weeks?after?application?there?were?few?differences?in?tissue?N?as?affected?by?N?source?(Table? 13).? Soil?Nitrogen,?Carbon,?and?Microbial?Biomass? ? In?2009,?there?was?little?significant?difference?in?soil?extractable?inorganic?N?(NH 4 ?N?plus? NO 3 ?N)?between?all?treatments?(Table?14).??Plots?fertilized?with?urea?had?higher?soil?inorganic?N? levels?than?all?other?plots?1?week?after?application.??Plots?fertilized?with?Milorganite,?Sustane?? (4?6?4),?TOP?(regular?grade),?and?NatureSafe?StressGuard?had?a?132,?120,?113,?and?71%?increase? in?extractable?soil?N?between?3?and?4?WAT.??Plots?fertilized?with?TOP?(fine?grade),?urea,?and? NatureSafe?Starter?had?a?162,?148,?and?110%?increase?in?soil?N?levels?between?weeks?4?and?6? after?application.??By?week?6?all?plots?including?the?control?had?much?higher?soil?N?levels?than?at? 29? ? week?1,?indicating?that?mineralization?of?N?from?organic?residue?such?as?clippings?or?thatch?was? occurring.??Ammonium?accounted?for?about?90%?of?soil?extractable?inorganic?N,?and?soil?NO 3 ? was?low?in?all?plots?during?the?2009?study?(Tables?15?and?16).? In?2010,?there?were?few?consistent?differences?in?inorganic?N?due?to?N?source?(Table?17).?? Application?of?any?product?increased?extractable?soil?inorganic?N?over?that?measured?in?the? control?at?1?week?after?application.??Unlike?2009?data,?about?half?of?the?N?was?in?NH 4 ?N?form? (Table?18)?and?about?half?was?in?the?NO 3 ?N?form?(Table?19).? `? Soil?total?N?and?C?values?were?rarely?affected?by?N?source?in?2009?and?2010?studies? (Tables?20,?21,?22,?and?23).??There?was?no?major?difference?in?total?N?amongst?all?treatments?as? compared?to?the?control?(Tables?20?and?21).??Studies?have?shown?that?mature?established? bermudagrass?turf?can?sustain?growth?from?naturally?mineralized?N?located?in?the?thatch?layer? and?soil?organic?N?pools,?releasing?between?60?to?154?kg?N?ha ?1 ?growing?season ?1 ?(Lee?et?al.,? 2003).??Lee?et?al.?(2003)?also?determined?that?substantial?growth?from?the?unfertilized?plots?of? bermudagrass?showed?evidence?of?sufficient?mineralization?for?turf?nutrition.? ? This?research?consisted?of?two?one?year?studies,?and?any?significant?affect?on?soil? organic?N?or?C?would?be?unlikely?in?this?short?time?period.??A?similar?study?found?no?differences? in?microbial?populations?or?total?N?when?hybrid?bermudagrass?was?fertilized?with?natural? organic?fertilizer?or?IBDU?(Elliott?and?Des?Jardin,?1999).? Soil?microbial?biomass?was?measured?at?the?end?of?the?2010?study?(Table?24).??Most?of? the?true?organic?treatments?had?a?greater?numerical?microbial?biomass?compared?to?the?control;? however,?no?treatments?were?statistically?different.??The?bermudagrass?plots?were?established? 13?and?greater?than?14?years?ago?for?the?2009?and?2010?studies,?respectively.??Studies?suggest? 30? ? that?soil?type?does?not?affect?soil?microbial?biodiversity,?due?to?abundance?of?food?from? carbohydrates?and?C?in?the?soil?(Yao?et?al.,?2006).??Studies?also?suggest?that?as?turfgrass?maturity? increases?natural?soil?N?mineralization?efficiency?also?increases,?and?mature?unfertilized? turfgrass?can?mineralize?from?60?to?154?kg?N?ha ?1 ?growing?season ?1 .??Nitrifying?soil?microbes?are? at?peak?activity?between?30?and?35?C,?and?these?temperatures?were?reached?each?week?(Table? 25)?during?the?2010?study?(Shi?et?al.,?2006a).? Roots,?Shoots,?and?Rhizome/Stolons?? ? In?2009,?root?weight?and?rhizome/stolon?weight?were?never?affected?by?fertilizer? treatments?(Table?26).??Rhizomes,?stolons?and?roots?are?the?storage?organs?for?turf? carbohydrates,?and?often?are?less?likely?to?respond?to?N,?as?compared?to?variables?such?as?shoot? density?or?turf?color?(Guertal?and?Hicks,?2009).??The?following?treatments?produced?a? significantly?higher?shoot?density,?as?compared?to?the?control:?urea,?Milorganite,?NatureSafe? StressGuard,?and?TOP?(regular?grade).??Sources?with?the?smallest?particle?size?had?the?highest? shoot?densities?(urea,?Milorganite,?NatureSafe?StressGuard,?and?TOP?(regular)),?and?were?often? sources?that?produced?best?color.??NatureSafe?Starter?had?the?smallest?rhizome/stolon?diameter,? while?Milorganite?and?Sustane??(4?6?4)?had?the?largest?rhizome/stolon?diameter.??All?other? treatments?were?not?different?from?either?group?(other?fertilizers?or?the?control).? ? In?2010,?there?were?no?differences?in?root?weight?among?treatments?until?the?last? sampling?date?(Table?27).??At?that?sampling,?12?weeks?after?application,?bermudagrass?fertilized? with?Milorganite?had?a?greater?root?weight?than?plots?fertilized?with?Scotts?Turf?Builder?or? NatureSafe.??Other?treatments?were?not?statistically?different?from?either?group.??Bermudagrass? shoot?densities?were?affected?by?N?source?at?the?first?sampling?date,?4?weeks?after?application.?? 31? ? Plots?fertilized?with?urea?had?the?highest?shoot?density,?although?not?significantly?different?from? the?control.??Most?treatments?generally?produced?a?higher?shoot?density?at?all?three?sampling? dates,?but?they?were?not?statistically?different?from?the?control.??Guertal?and?Hicks?(2009)? reported?that?N?source?did?not?affect?shoot?density.??There?were?differences?in?rhizome? diameter?for?the?first?and?second?sampling?dates?(4?and?9?WAT);?however,?results?were? inconsistent.? ? Laboratory?Incubation?Study? Mineralization? ? All?N?mineralization?incubation?studies?were?significantly?affected?by?N?source?and?a?N? source?x?temperature?interaction?(Tables?28?and?29).??The?data?generally?show?a?large?release?of? inorganic?N?within?the?first?two?weeks?after?application?followed?by?a?steady,?low?rate?of? mineralization?and?N?release.??The??transition??day?(intercept?of?two?statistical?N?release?models),? is?where?the?initial?rapid?mineralization?rate?changes?to?a?steady?state?mineralization?rate?(Table? 30).??Excluding?NatureSafe?StressGuard?(15?C),?all?treatments?completed?the?initial? mineralization?phase?within?two?weeks.??Recovery?of?mineralized?N?ranged?from?8.5?to?46.3%? during?the?initial?phase?and?16.6?to?66.5%?for?the?entire?study?for?all?treatments?and? temperature?regimes.??During?the?initial?phase,?mineralization?produced?mainly?NH 4 ?N?and?little? if?any?NO 3 ?N,?but?during?the?steady?state?phase?NO 3 ?N?was?the?dominant?species?produced? (Figures?7?13).? As?temperature?increased,?the??transition??day?generally?decreased,?indicating?a?higher? mineralization?rate,?most?likely?due?to?higher?microbial?activity.??Total?inorganic?N?recovery? 32? ? increased?for?all?treatments?from?15?to?25?C,?except?for?the?Sustane??(4?6?4)?fertilizer.??Sustane?? (4?6?4)?has?a?larger?particle?size?(Table?1)?than?any?other?treatment,?which?may?explain?the?low? recovery.??Sustane??(4?6?4)?had?its?largest?percent?of?N?recovery?at?35?C,?in?which?at?least?30%? more?inorganic?N?was?recovered?than?at?15?and?25?C.? ? The?Sustane??(4?6?4)?and?urea?treatments?(Figures?7?and?11)?had?an?overall?low? inorganic?N?recovery.??The?low?percent?of?N?recovery?from?lysimeters?fertilized?with?urea?is? somewhat?unexpected,?but?may?be?a?function?of?NH 3 ?volatilization.??Urea?has?been?shown?to? volatilize?upwards?of?50%?of?its?N?within?the?first?few?days?after?application?(Knight?et?al.,?2007).?? Urea?N?loss?through?volatilization?increases?with?higher?temperatures?and?larger?N?application? rates?(Overrein?and?Moe,?1966).??In?our?study?we?had?a?high?temperature?treatment?(35?C)? (Table?31),?which?would?increase?N?loss?through?volatilization.??Except?for?Sustane??(4?6?4)?and? urea,?all?other?treatments?had?a?decrease?in?inorganic?N?recovery?as?the?temperature?increased? from?25?to?35?C?(Figure?17).??This?is?in?agreement?with?Lee?et?al.?(2001)?where?optimum? mineralization?rates?occurred?between?28?and?38?C.??? Treatments?(urea,?Sustane?(4?6?4),?and?TOP?(fine?grade))?that?had?a?low?recovery?(less? than?30%?N?mineralized),?generally?had?a?transition?in?N?release?at?or?before?7?days?after? application?(Figures?7,?11,?and?12).??TOP?(regular?grade)?had?a?slightly?higher?increase?in?days? required?to?reach?the?transition?point,?as?compared?to?the?TOP?(fine?grade)?(Figures?12?and?13).?? TOP?(regular?grade)?had?a?slightly?higher?recovery?(about?10?to?13%)?than?TOP?(fine?grade),? which?would?explain?the?slight?increase?to?reach?the?transition.??The?particle?size?of?TOP?(regular? grade)?(Table?3)?is?about?58%?larger?than?TOP?(fine?grade),?because?these?two?treatments?have? identical?ingredients?and?N?solubility?ratings,?this?may?give?indication?of?a?reduced?volatility?due? to?particle?size.? 33? ? ??All?other?treatments?(Milorganite,?NatureSafe?Starter?and?StressGuard),?with?the? exception?of?Milorganite?at?35?C,?had?a?larger?percent?of?N?mineralized?(35?to?70%?N? mineralized),?which?increased?the?transition?day?beyond?the?one?week?mark.??These?treatments? have?the?largest?ratio?of?insoluble?N,?possibly?slowing?N?release?while?reducing?NH 3 ? volatilization,?and?thus?allowing?for?an?increase?in?N?recovery,??In?order?from?highest?to?lowest? inorganic?N?recovery?for?all?temperature?regimes:?NatureSafe?Starter,?NatureSafe?StressGuard,? Milorganite,?TOP?(regular?and?fine?grade),?Sustane??(4?6?4),?and?urea.??? 34? ? Summary? Field?Study? Two?separate?three?month?studies?evaluated?the?effects?of?organic?fertilizers?on?hybrid? bermudagrass?growth?and?performance.??In?general,?application?of?sources?with?large?portions? (or?100%)?of?soluble?N?(urea?and?Scotts?Turf?Builder)?produced?turf?with?a?dark?green?color,? higher?shoot?density,?and?greater?clipping?yield.??Although?organic?fertilizers?are?often?touted?as? maintaining?color?for?longer?periods?of?time,?it?was?not?the?case?in?this?study,?as?urea?provided? consistent?quality?color?for?the?same?8?10?week?period?as?the?organic?sources.??There?were?few? differences?in?soil?N,?C,?or?microbial?biomass.? ? Laboratory?Incubation?Study? Six?individual?ten?week?studies?(two?repetitions?per?temperature)?were?performed?at?15,? 25,?and?35?C.??Mineralization?of?organic?N?was?observed,?and?it?was?significantly?affected?by? treatment?and?a?treatment?x?temperature?interaction.??Optimum?mineralization?was?observed?at? 25?C,?with?the?least?amount?of?mineralization?occurring?at?15?C.??Ammonium?N?was?largely? produced?during?the?first?two?weeks?after?application,?switching?to?NO 3 ?N?after?that.??In?some? cases,?reduced?N?production?at?the?highest?soil?temperature?was?likely?due?to?N?loss?via?NH 3 ? volatilization.? 35? ? Literature Cited Ali,?M.A.,?J.H.?Hwan,?and?P.J.?Kim.?2008.?Evaluation?of?silicate?iron?slag?amendment?on?reducing? methane?emission?from?flood?water?rice?farming.?Ag.?Ecosystems?Environ.?128:21?26.? Anderson,?J.P.E.?1982.?Soil?Respiration.?In:?A.L.?Page,?R.H.?Miller,?and?D.R.?Keeney?(eds.).? Methods?of?Soil?Analysis.?Part?2.?2 nd ?ed.?Ag?Soc?Amer.,?Madison,?WI.? 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Sims,?J.T.?1990.?Nitrogen?mineralization?and?elemental?availability?in?soils?amended?with? composted?sewage?sludge.?J.?Environ.?Qual.?19:669?675.? Sims,?G.K.,?T.R.?Ellsworth,?and?R.L.?Mulvaney.?1995.?Microscale?determination?of?inorganic? nitrogen?in?water?and?soil?extracts.??Commun.?Soil?Sci.?Plant?Anal.?26:303?316.? Snyder,?G.H.,?B.J.?Augustin,?and?J.M.?Davidson.?1984.?Moisture?sensor?controlled?irrigation?for? reducing?nitrogen?leaching?in?bermudagrass?turf.?Agron.?J.?76:964?969.? Starr,?J.L.?and?H.C.?DeRoo.?1981.?The?fate?of?nitrogen?fertilizer?applied?to?turfgrass.?Crop?Sci.? 21:531?536.?? Thornton,?F.C.,?N.J.?Shurpali,?B.R.?Bock,?and?K.C.?Reddy.?1998.?N 2 O?and?NO?emissions?from? poultry?litter?and?urea?applications?to?bermudagrass.?Atmospheric?Environ.?32:1623?1630.? 43? ? Tian,?G.,?T.C.?Granato,?F.D.?Dinelli,?and?A.E.?Cox.?2008.?Effectiveness?of?bio?solids?in?enhancing? soil?microbial?populations?and?nitrogen?mineralization?in?golf?course?putting?greens.?Appl.? Soil?Ecol.?40:381?386.? Tomaso?Peterson,?M.?and?D.H.?Perry.?2007.?The?role?of?bio?fungicides?and?organic?fertilizer?in? the?management?of?dollar?spot?in?bermudagrass.?Online.?Applied?Turfgrass?Sci.? doi:10.1094/ATS?2007?0911?01?RS.? Torello,?W.A.,?D.J.?Wehner,?and?A.J.?Turgeon.?1983.?Ammonia?volatilization?from?fertilized? turfgrass?stands.?Agron.?J.?75:454?457.? Trenholm,?L.E.?and?J.B.?Unruh.?2005.?Warm?season?turfgrass?response?to?fertilizer?rates?and? sources.?J.?Plant?Nutri.?28:991?999.? U.S.?Department?of?Energy.?2008.?U.S.?Department?of?Labor,?Mine?Safety?and?Health? Administration,?Form?7000?2,?"Quarterly?Mine?Employment?and?Coal?Production?Report."? Released?2009.?http://www.eia.doe.gov/cneaf/coal/page/acr/table1.html? Warman,?P.R.,?J.C.?Burnham,?and?L.J.?Eaton.?2009.?Effects?of?repeated?applications?of?municipal? solid?waste?compost?and?fertilizers?to?three?low?bush?blueberry?fields.?Sci.?Hort.?122:393? 398.? Warnke,?S.?2003.?Creeping?bentgrass?(Agrostis?stolonifera?L.).?p.?175?185.?In?M.D.?Casler?and? R.R.?Duncan?(ed.)?Turfgrass?biology,?genetics,?and?breeding.?John?Wiley?and?Sons,?Hoboken,? NJ.? ? Watts,?D.B.,?H.A.?Torbert,?and?S.A.?Prior.?2007.?Mineralization?of?nitrogen?in?soils?amended?with? dairy?manure?as?affected?by?wetting/drying?cycles.?Commun.?Soil?Sci.?Plant?Anal.?38:2103? 2116.? Webster,?C.P.,?and?R.J.?Dowdell.?1982.?Nitrous?oxide?emission?from?permanent?grass?swards.?J.? Sci.?Food?Agric.?33:227?230.? Williams,?E.J.,?G.L.?Hutchinson,?and?F.C.?Fehsenfeld.?1992.?NO x ?and?N 2 O?emissions?from?soils.? Global?Biogeochem.?Cycles.?6:351?388.? Wu,?L.,?R.?Green,?M.V.?Yates,?P.?Pacheco,?and?G.?Klein.?2007.?Nitrate?leaching?in?overseeded? bermudagrass?fairways.?Crop?Sci.?47:2521?2528.? Yao,?H.,?D.?Bowman,?and?W.?Shi.?2006.?Soil?microbial?community?structure?and?diversity?in?a? turfgrass?chronosequence:?Land?use?change?versus?turfgrass?management.?Appl.?Soil?Eco.? 34:209?218.? Yao,?H.,?D.C.?Bowman,?T.?Rufty,?and?W.?Shi.?2009.?Interactions?between?nitrogen?fertilization,? grass?clipping?addition?and?pH?in?turf?ecosystems:?Implications?for?soil?enzyme?activities?and? organic?matter?decomposition.?Soil?Bio.?Biochem.?41:1425?1432.? ? ? ? ? 44 ? Table?1.?Initial?soil?test?values?(Mehlich?1?extractant)?for?the?two?research?areas,?TGRU,?Auburn,?AL.??0???5?cm?sampling?depth.? ?? ?? ?? Experiment?1? ???????? Experiment?2??? ?? ? 28?April?2009?? 5?May?2010 ?? ? mg?kg ?1 ?soil P? 28? 48? ? K? 47? 30? ? Mg? 36? 56? ? Ca? 273? 432? ? soil?N? 259? 542? ? soil?C? 7360? 10550? ? soil?pH? 6.6? 6.1? ? ? ? ? ? 45 ? ? Table?2.?Maintenance?fertilizer,?fungicides?and?herbicides?applied?to?the?two?field?studies,?TGRU,?2009?and?2010.? ? Fertilizer? Date?? Applied? Fungicide? Date? Applied? Pesticide? Date? Applied? Experi men t ? 1 ??? ?? ?? ??? ?? ?? ?? ??? ?? 28 ? April ? 2009 ? 0?0?60??40?lb?K?A ?1 ? 4/9/2009? Rubigan??1?lb?ai?A ?1 ?(W)? 6/11/2009? Escalade?2??1.5?qt?A ?1 ? 4/20/2009? Tartan??2?oz?1000ft ?2? (W)? 6/18/2009? Escalade?2??1.5?qt?A ?1 ? 5/1/2009? ?? Manor??0.5?oz?A ?1 ?(W)? 5/1/2009? ??Manor??0.5?oz?A ?1 ?(E)? 7/2/2009? ?? Merit??1.5?pt?A ?1 ?(W)? 7/12/2009? ??Escalade?2??1.5?qt?A ?1 ?(E)? 7/13/2009? Experi men t ? 2 ??? ?? ?? ??? ?? ?? ?? ??? ?? ? 5 ? May ? 2010 ? 0?0?60??80?lb?K?A ?1 ? 1/20/2010? Pro?Star??4.5?oz.?1000ft ?2 ? 4/29/2010? Revolver??0.4?oz?1000ft ?2 ?(S)? 4/9/2010? 0?46?0??1.0?lb?P?1000ft ?2 ? 1/27/2010?? ?Revolver??0.4?oz?1000ft ?2 ?(S)? 5/7/2010? ? Trimec?southern??1.5?pt?A ?1 ? 6/5/2010? ?? ?MSMA??1.5?1b?ai?A ?1 ? 6/5/2010? ? Trimec?southern??1.5?pt?A ?1 ? 6/17/2010? ?? ?MSMA??1.51b?ai?A ?1 ? 6/17/2010? ? ? ? 46 ? ? Table?3.?Selected?fertilizer?treatments?used?in?both?laboratory?incubation?and?field?research?studies.? ? ?? Trade?Name/Treatment??Analysis??? %N??w/w???? SGN??? ? ?? ?? ?? N?P 2 O 5 ?K 2 O??? AMM/WSN/WIN?? ? ?? Milorganite?(MILORG)???6?2?0??? 0/0.75/5.25??90?? ?? Nature?Safe?Starter?(NSS)???5?6?6??? 0.2/0.3/4.5??170?? ?? Nature?Safe?StressGuard?(NSSG)???8?3?5??? 0.2/0.6/7.2??160?? ?? Scotts?Turf?Builder?(STB)???32?0?10??? 2.8/9.6/0.9??????? 12.7%?urea?N? ? 90?? ?? Sustane??(ST4)???4?6?4??? 0.4/0.4/3.2??200?? ?? Sustane??(ST8)???8?2?4??? 0.4/0.4/7.2??100?? ?? Fine/Regular?(TOPF/TOPR)???4?2?2???0.0/0.42/3.58??100/170?? ?? Urea?(UREA)???46?0?0??? 46%?urea?N??110?? ??AMM?=?ammoniacal?nitrogen,?WSN?=?water?soluble?nitrogen,?WIN?=?water?insoluble?nitrogen? ??SGN?=?Size?Guide?Number,?which?is?the?average?particle?diameter?in?millimeters,?multiplied?by?100.? ? ? ? 47 ? Table?4.?Organic?ingredients?in?selected?fertilizer?treatments?used?in?both?laboratory?incubation?and?field?research?studies.? ?? Trade?Name/Treatment??Manufacturer? ?? Derived?from:?? ?? Milorganite?(MILORG)??? Milorganite?????????????????? Milwaukee,?WI? ?? composted?sewage?sludge??? ?? Nature?Safe?Starter?(NSS)??? Griffin?Industries,?Inc.????????? Cold?Spring,?KY.? ?? meat,?blood,?bone,?and?fish? meals,?and?langbeinite? ?? ?? Nature?Safe?StressGuard?(NSSG)??? Griffin?Industries,?Inc.????????? Cold?Spring,?KY.? ?? hydrolyzed?feather,?meat,? bone,?poultry,?and?fish?meals,? and?langbeinite? ?? ?? Scotts?Turf?Builder?(STB)??? The?Scotts?Company?LLC.? Marysville,?OH? ?? methylene?urea??? ?? Sustane??(ST4)?? Sustane?Natural?Fertilizer,? Inc.??Cannon?Falls,?MN.? ? aerobically?composted?turkey? litter,?feather?meal,?sulfate?of? potash? ?? ?? Sustane??(ST8)??? Sustane?Natural?Fertilizer,? Inc.?Cannon?Falls,?MN.? ?? aerobically?composted?turkey? litter,?hydrolyzed?feather? meal,?and?sulfate?of?potash? ?? ?? Fine/Regular?(TOPF/TOPR)??? Organic?Growing?Systems,? Inc.?Alpharetta,?GA.? ?? poultry?litter?and?feather? meal? ?? ?? Urea?(UREA)??? Tri?State?Plant?Food?Inc.??????? Dothan,?Al? ?? (NH 2 ) 2 CO??? ? ? ? 48 ? ? Table?5.?Fertilizer?pickup?by?mower?(g?per?plot)?as?affected?by?N?source,?2010,?Auburn,?AL.?? N???????????????? Source? Harvest?Date? ????????????????????? (weeks?after?application)? ? ? ? g?plot ?1 ? ??May?11???????????? (1)? May?17? ???????? (2)? UREA? 0.0?c??0.0?c??? MILORG? 0.5?c 0.0?c??? NSS??16.8?bc??0.0?c??? NSSG 1.4?c 0.0?c??? ST4? 41.8?a? 10.5?a??? TOPF? ???7.9?bc??0.0?c??? TOPR??1.5?c 0.0?c??? ST8? 21.9?b??4.3?b??? STB??0.5?c 0.0?c??? CNTRL 0.0?c??0.0?c??? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at? ??=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0?10),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic? Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 49 ? ? Table?6.?Visual?color?ratings?(1:brown???9:dark?green)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N??????????? Source? Harvest?Date?(days?after?application)? ?? April?28????? (1)? April?30???? (3)? May?2??????? (5)? May?5??????? (7)? May?12?? (14)? May?19?? (21)? May?26?? (28)? June2????? (35)? June?9??????? (42)? UREA? 2.00?b? 2.75?a? 3.00?a? 4.50?a? 5.00?a? 5.25?a? 6.00?a? 5.75a? 6.50?a? MILORG???2.50?ab? 2.50?a???2.50?ab???2.50?bc???3.25?bc? 4.00?b???4.50?cd???4.25cd???5.25?bc? NSS???2.50?ab? 2.25?a? 2.00?b???3.00?bc? 4.00?b? 4.25?b???5.50?ab? 5.50a? 6.25?a? NSSG??2.00?b? 2.00?a? 2.00?b? 2.00?c? 2.75?c? 4.25?b???5.00?bc???5.25ab? 5.50?b? ST4???2.25?ab? 2.75?a???2.50?ab???2.25?bc???3.25?bc???3.50?bc? 3.50?e???3.75de???4.50?cd? TOPF???2.50?ab? 2.50?a???2.50?ab???2.75?bc???3.50?bc???3.50?bc? 3.50?e???4.00de???5.25?bc? TOPR? 2.75?a? 2.75?a? 3.00?a???3.50?ab???3.50?bc? 4.00?b???4.00?de???4.75bc???5.25?bc? CNTRL???2.50?ab? 2.25?a???2.25?ab? 2.00?c? 2.75?c? 2.75?c? 2.75?f? 3.50?e? 4.25?d? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ?? ? ? ? 50 ? Table?6,?cont?d.?Visual?color?ratings?(1:brown???9:dark?green)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N??????? Source? Harvest?Date?(days?after?application)? ?? June?16??????????? (49)? June?23?????????? (56)? June?30?????????? (63)? July?7???????????? (70)? July?14?????????? ?? (77)? July?21???????????? ?? (84)? UREA? 7.00?a? 7.00?a? ????6.50?abc???7.00?ab???6.50?ab???5.75?ab? MILORG? ????6.00?abc???6.75?ab???6.75?ab???7.25?ab???6.50?ab???6.00?ab? NSS???6.50?ab? 7.00?a? 7.00?a? 7.50?a? 6.75?a? 6.25?a? NSSG? ????6.00?abc???6.25?ab? ????6.50?abc???7.00?ab? 6.75?a? 6.25?a? ST4???5.50?bc???6.25?ab? ????6.25?abc???6.00?bc???5.75?ab???5.50?ab? TOPF? 5.25?c? 5.75?b???6.00?bc???6.00?bc???6.50?ab???5.50?ab? TOPR???5.50?bc???6.25?ab? ????6.25?abc???7.00?ab???6.50?ab???6.00?ab? CNTRL? 5.25?c???6.00?ab? 5.75?c? 5.25?c? 5.50?b? 5.25?b? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? ? ? 51 ? Table?7.?Visual?color?ratings?(1:poor???9:lush?green)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,?AL.? N? Source? Harvest?Date?(days?after?application)? ?? May?5?????? (1)? May?7????? (3)? May?9????? (5)? May?11?????? (7)? May?17? (14)? May?24?? (21)? June?1???? (28)? June?7?????? (35)? June?14? (42)? UREA? 3.50?a? 4.50?a? 4.50?a? 4.75?a???7.75?ab? 8.00?a???7.75?ab? 8.00?a? 6.50?a? MILORG? 3.00?a? 3.00?b? 3.25?b? 3.50?b? 5.25?c???6.25?bc???6.25?cd???6.50?cd???5.25?bc? NSS? 3.25?a? 3.00?b? 3.25?b???3.00?bc? 6.75?b? 7.75?a? 8.00?a? ???7.75?ab? ????6.00?abc? NSSG? 3.00?a? 3.00?b? 3.00?b???3.00?bc???4.50?cd? 6.50?b? ????7.00?abc? 8.00?a???6.25?ab? ST4? 3.00?a? 3.00?b? 3.00?b???3.00?bc???4.50?cd???5.25?cd???5.50?de? ????6.75?bcd? ????5.75?abc? TOPF? 3.00?a? 3.00?b? 3.00?b???3.25?bc???4.25?cd? 4.50?d???5.00?ef? 6.00?d???5.25?bc? TOPR? 3.00?a? 3.00?b? 3.00?b???3.25?bc? 5.25?c???6.00?bc???6.25?cd? ????7.00?abc???5.00?cd? ST8? 3.25?a? 3.50?b? 3.00?b???3.00?bc???4.25?cd???5.75?bc???6.75?bc???7.75?ab? 6.75?a? STB? 3.00?a? 4.25?a? 4.50?a? 4.75?a? 8.25?a? 8.50?a???7.75?ab???7.75?ab???5.25?bc? CNTRL? 3.00?a? 3.00?b? 2.75?b? 2.75?c? 3.75?d? 3.00?e? 4.25?f? 4.25?e? 4.00?d? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at??? =?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?,?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder? (32?0?10)CNTRL?unfertilized?control? ? ? ? ? 52 ? ? Table?7,?cont?d.?Visual?color?ratings?(1:poor???9:lush?green)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,? AL.? N??? Source? Harvest?Date?(days?after?application)? ?? June?21????????? (49)? June?28????????? (56)? July?6?? ????????? (63)? July?12?????????? ? (70)? July?19?????????? ? (77)? July?27?????? ?????? (84)? UREA? 6.25?a???6.75?ab? 7.00?a? 6.00?a???6.75?ab? 7.00?a? MILORG???5.75?ab???5.75?ab???5.50?ab? 5.75?a???6.00?ab? 6.75?a? NSS? 6.50?a???7.00?ab???5.25?ab? 5.25?a???6.50?ab? 7.25?a? NSSG? 6.75?a? 7.25?a???6.00?ab? 6.25?a???7.00?ab? 7.75?a? ST4? 6.25?a???6.50?ab???6.00?ab? 5.25?a???6.50?ab? 7.25?a? TOPF???5.25?ab???5.75?ab???5.5?ab? 5.00?a???6.50?ab? 7.00?a? TOPR???6.00?ab???5.50?ab? 4.5?b? 5.25?a? 5.25?b? 6.00?a? ST8? 6.75?a???6.75?ab???5.75?ab? 5.00?a? 7.25?a? 7.00?a? STB? 6.50?a???6.50?ab???5.50?ab? 5.75?a???6.50?ab? 7.00?a? CNTRL? 4.50?b? 5.25?b? 4.25?b? 5.75?a???5.75?ab? 6.50?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),? ST4?Sustane??(4?6?4),?,?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),? STB?Scotts?Turf?Builder?(32?0?10)CNTRL?unfertilized?control? ? ? ? 53 ? ? Table?8.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N??????????????? Source? Harvest?Date?(weeks?after?application)? ?? May?5??? ??????? (1)? May?12 ??????????? (2)? May?19?? ??????? (3)? May?26???? ????? (4)? June?2?? ???????? (5)? June?9?? ?????????? (6)? UREA? 153.0?a? 148.5?a? 179.8?a? 250.3?a? 247.3?a? 237.8?a? MILORG???138.3?ab???137.8?ab? 149.0?c???196.5?bc? 198.5?c? 197.3?b? NSS? 143.8?ab? 136.8?b???169.5?ab? 247.5?a???230.0?ab? 234.8?a? NSSG? 129.0?b???123.5?cd???150.0?bc???221.8?ab? 221.8?b? 225.8?a? ST4? 131.5?b? 120.3?d? 123.3?d? 162.5?d? 154.3?d? 160.5?c? TOPF???139.0?ab? ????127.8?bcd???133.8?cd???181.3?cd? 165.0?d???180.3?bc? TOPR???147.0?ab???135.0?bc???150.3?bc???205.3?bc? 196.0?c? 201.5?b? CNTRL???135.5?ab? ????130.5?bcd? 123.8?d? 152.8?d? 152.0?d? 160.8?c? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 54 ? ? Table?8,?cont?d.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N?????? Source? Harvest?Date?(weeks?after?application)? ?? June?16???????????? (7)? June?23? ???????? (8)? June?30? ???????? (9)? July?7???????????? (10)? July?14?? ????????? (11)? July?21 ??????????? (12)? UREA? 251.8?a? 258.0?a???219.5?ab???261.8ab???236.3?ab???226.5?ab? MILORG???218.8?bc? 251.5?a???216.0?ab???259.8ab? 240.0?a? 234.3?a? NSS???245.3?ab? 267.0?a? 233.8?a? 273.5?a? 255.8?a? 239.5?a? NSSG???248.5?ab? 253.0?a???225.0?ab???264.0?ab? 252.8?a? 234.0?a? ST4? 178.3?d? 197.5?c? 179.8?c? 220.0?c? 204.8?c? 201.3?c? TOPF???194.8?cd???219.8?bc???195.0?bc???239.3?bc???214.0?bc???209.5?bc? TOPR???227.0?ab???245.3?ab???216.8ab???255.0?ab? 249.5?a? 235.8?a? CNTRL? 176.8?d? 210.3?c? 178.0?c? 222.8?c? 212.8?c???204.8?bc? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),? ST4?Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized? control? ? ? ? ? ? 55 ? ?Table?9.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,?AL.? N????? Source? Harvest?Date?(weeks?after?application)? ?? May11???????????? (1)? May?17???????????? (2)? May?24?????????? (3)? June?1?????????????? (4)? June?7?????????????? (5)? June?14??????????? (6)? UREA? 330.3?a? 406.3?a? 368.0?a???370.2?ab? 383.5?a? ????350.8?abc? MILORG? 291.5?b? 327.8?bc? 300.8?bc???310.5?de? ????279.8?bcd???317.5?cd? NSS? 288.3?b? 349.8?b? 324.0?b? ????358.5?abc? ????321.8?abc???356.5?ab? NSSG? 267.3?b???299.3?cd???303.5?bc? ????339.8?bcd???331.3?ab? 368.5?a? ST4? 278.3?b???290.8?de???282.3?cd???316.0?de? ????277.8?bcd? ????322.0?bcd? TOPF? 285.5?b???306.5?cd???275.0?cd???302.3?de???259.0?cd? 303.8?d? TOPR? 284.3?b???306.8?cd???271.8?cd? 290.8?e? ????273.5?bcd? 302.8?d? ST8? 270.8?b???302.3?cd???276.0?cd? ????325.8?cde???311.0?bc? ??????332.5?abcd? STB? 328.3?a? 408.3?a? 370.3?a? 388.0?a???341.5?ab? 358.3?a? CNTRL? 264.8?b? 264.8?e? 244.8?d? 251.5?f? 234.5?d? 264.0?e? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB? Scotts?Turf?Builder?(32?0?10),?CNTRL?unfertilized?control? ? ? ? 56 ? ? Table?9,?cont?d.?Chlorophyll?meter?(reflectance)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,?AL.? N????? Source? Harvest?Date?(weeks?after?application)? ?? June?21???????????? (7)? June?28 ?????????? (8)? July?6? ?????????? (9)? July?12???????????? (10)? July?19 ?????????? (11)? July?27 ?????????? (12)? UREA? ????264.0?abc? ???????322.3?abcd? 324.3?a? 309.8?a? 336.5?a? 382.5?a? MILORG? ??????258.8?abcd? ????308.0?bcd? 303.5?a? 308.8?a? 312.8?a? 373.8?a? NSS???280.5?ab? 336.5?a? 308.0?a? 305.3?a? 328.0?a? 374.8?a? NSSG? 284.3?a???335.0?ab? 307.5?a? 317.7?a? 337.0?a? 391.3?a? ST4? ????274.8?abc? ???????324.0?abcd? 308.3?a? 304.5?a? 330.3?a? 376.3?a? TOPF???250.8?cd? ???????311.3?abcd? 303.5?a? 298.8?a? 330.5?a? 381.3?a? TOPR? ????256.3?bcd???303.8?cd? 296.3?a? 301.0?a? 306.3?a? 365.0?a? ST8? ????268.8?abc? ????328.0?abc? 306.3?a? 296.8?a? 339.0?a? 375.3?a? STB???281.0?ab? ????329.5?abc? 301.8?a? 312.8?a? 331.0?a? 391.8?a? CNTRL? 233.3?d? 298.8?d? 298.3?a? 317.8?a? 322.5?a? 382.8?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),? ST4?Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),? STB?Scotts?Turf?Builder?(32?0?10),?CNTRL?unfertilized?control? ?? ? ? ? 57 ? ? Table?10.?Clipping?yield?(grams?per?plot)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,Auburn,?AL.? N????? Source? Harvest?Date?(weeks?after?application)? ?? May?5????? (1)? May?12??? (2)? May?19??? (3)? May?26??? (4)? June?2???? (5)? June?9???? (6)? June?16???? (7)? June?23??? (8)? June?30??? (9)? July?7????? (10)? July?14??? (11)? July?21??? (12)? UREA???10.8?ab? 1.9?a? 1.9?a? 4.2?a? 9.1?a? 3.8?a? 5.0?a? 4.8?a? 6.7?a???7.5?ab???2.0?ab? 2.4?a? MILORG???11.2?ab? ????0.9?bcd? 0.6?b? 1.3?b? 4.7?b? 2.0?c? ????3.8?abc???3.3?ab? ????4.6?abc ????5.1?abc? ????1.7?abc???1.8?ab? NSS? 14.3?a? 1.3?b? 0.9?b? 3.7?a? 6.7?a???3.4?ab???4.5?ab? 4.5?a? 6.4?a? 7.9?a? 2.3?a? 2.5?a? NSSG???8.7?b? 0.5?d? 0.8?b? 2.2?b? 5.3?b???2.3?bc? ????3.7?abc???3.4?ab???5.7?ab? ????5.7?abc???2.1?ab???2.2?ab? ST4???9.5?ab? 0.5?d? 0.4?b? 1.0?b? 3.8?b? 1.1?c? 1.6?d? 2.0?b? 2.6?c? 4.0?c? 1.1?c? 1.3?b? TOPF???9.9?ab? ????0.9?bcd? 0.3?b? 1.4?b? 3.9?b? 1.5?c? 1.8?d? 2.2?b???3.3?bc? ????5.1?abc???1.3?bc? 1.4?b? TOPR? 12.6?ab???1.1?bc? 0.6?b? 2.3?b? 4.8?b? 2.0?c? ????3.2?bcd? 2.5?b? ????4.5?abc ????5.9?abc? ????1.9?abc???2.0?ab? CNTRL? 12.5?ab???0.7?cd? 0.4?b? 1.3?b? 4.2?b???2.1?bc???2.4?cd? 2.5?b? 2.8?c???4.7?bc? 1.1?c???1.7?ab? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6? 4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 58 ? ? Table?11.?Clipping?yield?(grams?per?plot)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,Auburn,?AL.? N???Source? Harvest?Date?(weeks?after?application)? ?? May?11??? (1)? May17? (2)? May?24?? (3)? June?1???? (4)? June?7??? (5)? June?14??? (6)? June?21??? (7)? June?28 ?? (8)? July?6????? (9)? July?12?? (10)? July?19? (11)? July?27? (12)? UREA? 66.5?a? 54.0?a? 47.8?a??40.7?a???45.5?ab 37.5?ab??14.6?ab? ???94.2?ab 51.4?a? 20.9?a? 27.3?a? 36.9?a? MILORG? 66.7?a???33.3?ab???22.3?bc ????19.0?cde????27.5?def ????19.3?def ??7.1?ab???58.5?b???34.8?bc? 14.7?a? 18.5?a? 21.2?a? NSS? 73.8?a???44.8?ab? 30.1?b? 32.3?b???40.3?bc ????30.2?bcd ?14.2?ab???63.0?b? ????42.2?abc 17.2?a? 21.9?a? 27.2?a? NSSG? 39.7?a? 25.7?b???21.4?bc ??22.9?cd???32.7?cd ????31.7?abc ?13.4?ab???57.5?b? ????42.0?abc 17.3?a? 20.1?a? 29.5?a? ST4? 56.7?a???36.5?ab???19.0?bc ????15.8?cde ??20.2?ef???16.1?ef???7.0?ab???59.3?b? ????37.4?abc 15.0?a? 20.0?a? 22.5?a? TOPF? 61.7?a???47.9?ab???22.2?bc ????19.4?cde????26.1?def ??14.6?ef???6.8?ab???54.4?b? ????38.8?abc 16.5?a? 19.0?a? 28.6?a? TOPR? 28.3?a? 29.5?b???19.6?bc ??14.7?de???18.6?ef???15.9?ef? 4.1?b???50.3?b???35.6?bc? 14.7?a? 17.7?a? 23.5?a? ST8? 63.9?a???34.9?ab???26.6?bc 24.0?c???29.2?de ????23.7?cde ?12.7?ab???46.9?b? ????42.8?abc 17.4?a? 20.6?a? 30.0?a? STB? 41.1?a???41.8?ab? 44.6?a? 41.6?a? 54.0?a? 42.9?a? 18.9?a? 121.2?a???49.0?ab? 21.2?a? 26.7?a? 34.3?a? CNTRL? 50.5?a? 31.3?b? 16.8?c? 12.5?e? 17.4?f? 10.2?f? 3.2?b???64.3?b? 31.9?c? 15.1?a? 19.7?a? 26.6?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at??? =?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade???(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder? (32?0?10),?CNTRL?unfertilized?control? ? ? ? ? 59 ? ? Table?12.?Tissue?N?(g?N?kg ?1 ?tissue)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N???Source? Harvest?Date?(weeks?after?application)? ?? May?5?????? (1)? May?12??? (2)? May?19???? (3)? May?26??? (4)? June2???? (5)? June?9????? (6)? June?16?????? (7)? June?23???? (8)? June?30?? (9)? July?7????? (10)? July?14??? (11)? July?21??? (12)? UREA? 29.0?a? 35.5?a? 32.0?a? 34.6?a? 31.3?a? 26.9?a? 27.1?a? 25.5?a? 24.7?a? 21.3?a? 21.0?a?? 20.8?b? MILORG? ????23.9?bcd? 28.8?c???28.9?bc???30.9?cd 27.9?c? 25.8?a? ??????25.4?abcd? ????24.7?abc 25.6?a? 21.3?a? 21.9?a???23.0?ab NSS???24.4?bc? 32.4?b???30.1?ab???33.5?ab ??30.1?ab 21.6?a???26.2?ab???25.4?ab? 25.5?a? 20.4?a? 22.1?a? 23.7?a? NSSG???22.9?cd???30.7?bc???28.6?bc???32.5?bc ??29.0?bc 27.1?a? ????25.7?abc? ????24.7?abc 24.9?a? 20.1?a? 19.4?a???22.3?ab ST4???23.0?cd? 28.1?c???26.9?cd? 28.4?e? 25.3?d? 24.8?a? 23.6?d? 23.1?d? 23.8?a? 20.5?a? 21.2?a? 20.9?b? TOPF? 24.9?b? 28.3?c? 26.4?d? ??29.3?de 25.9?d? 25.0?a? ????25.0?bcd? ????24.0?bcd 24.5?a? 21.1?a? 20.5?a? ??21.5?ab TOPR???24.5?bc? 29.0?c???27.2?cd???30.1?de ??27.2?cd 25.8?a? ??????25.4?abcd? ????24.8?abc 24.5?a? 16.5?a? 21.2?a???22.3?ab CNTRL? 22.5?d? 27.8?c? 26.2?d? 28.4?e? 25.2?d? 24.1?a? 24.0?cd???23.4?cd? 23.3?a? 18.5?a? 19.6?a? 20.7?b?? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?(4?6? 4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 60 ? ? Table?13.?Tissue?N?(g?N?kg ?1 ?tissue)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,?Auburn,?AL.? N????Source? Harvest?Date?(weeks?after?application)? ?? May?11? (1)? May17? (2)? May?24???? (3)? June?1?? ??? (4)? June?7???? (5)? June?14? (6)? June?21??? (7)? June?28??? (8)? July?6???? (9)? July?12? (10)? July?19? (11)? July?27??????? (12)? UREA? 34.2?a? 35.6?a? 33.2?a? 31.7?a? 32.5?a???33.1?ab 34.8?a? 32.9?a? 35.3?a? 34.3?a? 31.4?a? 30.2?a? MILORG???28.2?bc???30.3?bc? ????29.7?abc ????27.7?bcd 28.6?c???33.7?ab 34.5?a? 32.6?a? 34.4?a? 32.1a? 29.6?a???27.2?cd? NSS? 30.7?b? 32.2?b???32.0?ab? ????30.5?ab???31.5?ab ??34.0?ab 34.5?a? 32.8?a? 34.4?a? 33.0?a? 31.6?a? ????27.8?bcd? NSSG???28.6?bc???29.5?bc? ????29.9?abc ????30.2?abc 32.7?a???34.0?ab 35.0?a? 32.6?a? 34.8?a? 32.5?a? 31.8?a? ????27.6?bcd? ST4???29.6?bc???29.2?bc? ????30.5?abc ????28.7?abc 29.2?c???33.1?ab 34.5?a? 31.5?a? 34.4?a? 32.6?a? 30.2?a? ??????28.8?abcd TOPF? 28.0?c???29.8?bc? 27.4?c???26.9?cd? 28.2?c???32.1?ab 33.7?a? 33.2?a? 27.3?a? 32.6?a? 31.3?a? ??????28.9?abcd TOPR???28.7?bc???29.3?bc? 27.6?c? 24.3?d? 28.4c? 31.5?b? 33.2?a? 31.5?a? 33.9?a? 32.0?a? 29.3?a? 26.8?d? ST8???28.6?bc???29.9?bc???28.6?bc? ????28.9?abc ??29.8?bc 35.6?a? 34.3?a? 33.5?a? 34.3?a? 32.8?a? 31.8?a???29.6?ab? STB? 34.7?a? 36.8?a? 33.4?a? 31.3?a? 32.6?a???33.8?ab 34.0?a? 31.7?a? 34.5?a? 33.8?a? 29.8?a? ????29.3?abc? CNTRL? 27.8?c? 27.9?c? 27.0?c? 25.2?d? 25.7?d? 31.7?b? 32.8?a? 32.2?a? 34.2?a? 32.7?a? 31.3?a? ??????28.7?abcd ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0?10),?CNTRL? unfertilized?control? ? ? ? ? 61 ? ? ? Table?14.?Inorganic?N?(mg?N?kg ?1 ?soil)?(NO 3 ?N?+?NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2009,?Auburn,?AL.? N?????? Source? Harvest?Date?(weeks?after?application)? ? May?5????????????? (1)? May?12 ????????? (2)? May?19 ??????????? (3)? May?26??????????? (4)? June2? ??????????? (5)? June?9 ???????????? (6)? UREA? 8.48?a? 7.46?a? 5.27?a???4.79?a???9.39?a? ????11.86?ab? MILORG? 5.54?b???6.54?ab? 4.39?a? 10.18?a???9.02?a? ????10.74?ab? NSS? 5.65?b???6.89?ab? 5.20?a???5.24?a???9.27?a? ????11.01?ab? NSSG? 4.45?b???6.51?ab? 5.12?a???8.76?a???8.80?a? ???7.99?b? ST4? 4.35?b???5.54?ab? 4.15?a???9.15?a???8.91?a? ?????9.62?ab? TOPF? 5.20?b? 5.33?b? 4.55?a???5.34?a???8.47?a???13.97?a? TOPR? 5.18?b???5.46?ab? 4.44?a???9.47?a? 10.30?a? ???10.24?ab? CNTRL? 4.50?b???5.42?ab? 4.40?a???4.94?a???7.56?a? ???10.36?ab? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 62 ? ? Table?14,?cont?d.?Inorganic?N?(mg?N?kg ?1 ?soil)?(NO 3 ?N?+?NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2009,?Auburn,?AL.? N???????????????? Source? Harvest?Date?(weeks?after?application)? ?? June?16????????????? (7)? June?23? ?????????? (8)? June?30 ??????????? (9)? July?7 ????????????? (10)? July?14 ?????????? (11)? July?21? ????????? (12)? UREA? 10.47?a? 4.23?a? 7.53?a???3.76?ab? ???5.89?ab? 4.30?a? MILORG? ???8.67?ab? 4.68?a? 8.39?a???3.21?ab? ???5.72?ab? 4.28?a? NSS? ???9.10?ab? 5.31?a? 8.20?a???5.75?ab? ???5.77?ab? 4.46?a? NSSG??5.86?b? 4.01?a? 8.07?a? 6.50?a? ???5.74?ab? 4.55?a? ST4? ???9.00?ab? 8.17?a? 7.30?a? 2.53?b? 5.17?b? 4.05?a? TOPF? ???8.19?ab? 7.29?a? 6.87?a? 2.45?b? ???5.56?ab? 4.92?a? TOPR? ???8.75?ab? 7.11?a? 7.91?a???4.92?ab? 7.60?a? 4.08?a? CNTRL? ???7.46?ab? 5.06?a? 7.68?a???4.47?ab? 4.64?b? 3.85?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation? at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 63 ? ? Table?15.?Ammonium?N?(mg?N?kg ?1 ?soil)?(NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2009,?Auburn,?AL.? N???? Source? Harvest?Date?(weeks?after?application)? ? May?5???? (1)? May?12??? (2)? May?19??? (3)? May?26??? (4)? June?2???? (5)? June?9???? (6)? June?16??? (7)? June?23??? (8)? June?30??? (9)? July?7????? (10)? July?14??? (11)? July?21??? (12)? UREA? 7.12?a? 7.16?a? 4.93?a? 4.22?a? 5.56?a? 11.10?a? 10.47?a? 4.23?a? 7.47?a? 2.17?b???5.63?ab 3.71?a? MILORG???4.96?ab???6.02?ab? 4.08?a? 4.69?a? 6.82?a???9.81?a? ????8.62?ab 4.68?a? 8.38?a? 1.81?b? 5.04?b? 3.82?a? NSS???5.24?ab???6.37?ab? 4.99?a? 4.46?a? 6.60?a???8.80?a? ????8.93?ab 5.31?a? 7.80?a? 3.04?b? 5.13?b? 4.07?a? NSSG? 4.21?b???5.66?ab? 4.68?a? 4.56?a? 5.70?a???7.19?a???5.84?b? 4.01?a? 7.99?a? 5.43?a???5.52?ab 4.05?a? ST4? 4.05?b???5.19?ab? 3.89?a? 3.94?a? 7.08?a???9.01?a? ????9.00?ab 7.67?a? 6.96?a? 1.38?b? 4.57?b? 3.33?a? TOPF???4.96?ab???5.17?ab? 4.17?a? 4.69?a? 6.45?a? 11.19?a? ????8.19?ab 7.29?a? 6.65?a? 1.32?b? 5.03?b? 4.55?a? TOPR???4.70?ab? 5.07?b? 4.29?a? 4.47?a? 8.07?a???8.65?a? ????8.75?ab 7.11?a? 7.91?a? 2.78?b? 7.33?a? 3.51?a? CNTRL? 4.11?b???5.12?ab? 4.09?a? 4.65?a? 6.00?a???8.97?a? ????7.46?ab 4.46?a? 7.64?a? 2.04?b? 4.33?b? 3.47?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at??? =?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? 64 ? ? Table?16.?Nitrate?N?(mg?N?kg ?1 ?soil)?(NO 3 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2009,?Auburn,?AL.? N???? Source? Harvest?Date?(weeks?after?application)? ?? May?5???? (1)? May?12??? (2)? May?19??? (3)? May?26??? (4)? June?2???? (5)? June?9???? (6)? June?16??? (7)? June?23??? (8)? June?30??? (9)? July?7????? (10)? July?14???? (11)? July?21??? (12)? UREA? 1.36?a???0.30?ab? 0.34?a? 0.58?a? 3.83?a? 0.77?a? 0.00?b? 0.00?a? 0.06?a? 1.59?a? 0.26?a? 0.60?a? MILORG? 0.58b???0.52?ab? 0.31?a? 5.49?a? 2.21?b? 0.93?a???0.05?ab 0.00?a? 0.01?a? 1.39?a? 0.68?a? 0.46?a? NSS? 0.41?b???0.52?ab? 0.21?a? 0.78?a???2.66?ab 2.21?a? 0.17?a? 0.00?a? 0.40?a? 2.71?a? 0.64?a? 0.38?a? NSSG? 0.23?b? 0.85?a? 0.44?a? 4.20?a???3.10?ab 0.80?a? 0.00?b? 0.00?a? 0.08?a? 1.07?a? 0.22?a? 0.50?a? ST4? 0.30?b???0.35?ab? 0.26?a? 5.21?a? 1.83?b? 0.61?a? 0.00?b? 0.50?a? 0.34?a? 1.15?a? 0.61?a? 0.72?a? TOPF? 0.24?b? 0.16?b? 0.37?a? 0.65?a? 2.02?b? 2.78?a? 0.00?b? 0.00?a? 0.22?a? 1.12?a? 0.53?a? 0.38?a? TOPR? 0.48?b???0.39?ab? 0.15?a? 5.00?a? 2.23?b? 1.59?a? 0.00?b? 0.00?a? 0.00?a? 2.14?a? 0.28?a? 0.57?a? CNTRL? 0.38?b???0.30?ab? 0.31?a? 0.12?a? 1.56?b? 1.39?a? 0.00?b? 0.59?a? 0.04?a? 2.43?a? 0.31?a? 0.38?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at??? =?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 65 ? ? Table?17.?Inorganic?N?(mg?N?kg ?1 ?soil)?(NO 3 ?N?+?NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2010,?Auburn,?AL.? N???? Source? Harvest?Date?(weeks?after?application)? ?? May?11?? (1)? May?17???? (2)? May?24? (3)? June?1? (4)? June?7???? ? (5)? June?14??? (6)? June?21??? (7)? June?28??? (8)? July?6???? (9)? July?12? (10)? July?19? (11)? July?27??? (12)? UREA???6.13?ab???6.64?ab? 5.20?a? 6.25?a? 6.07?b???8.56?a? 9.72?a? 9.83?a? 7.19?a???4.29?bc???7.56?a? 7.65?a? MILORG???6.70?ab???6.51?ab? 4.14?a? 5.52?a? 8.77?a???9.72?a? 8.61?a? 7.41?b? 6.61?a???3.96?bc???9.02?a? 6.91?a? NSS? 8.08?a? 8.74?a? 4.55?a? 6.20?a???7.27?ab???8.39?a? 8.58?a???7.81?ab? 7.00?a? ????4.62?abc 12.83?a? 6.25?a? NSSG? 7.71?a???8.09?ab? 5.65?a? 6.25?a? 5.14?b???9.61?a? 9.80?a? 7.43?b? 7.37?a???4.39?bc? 11.81?a? 5.99?a? ST4???6.01?ab???7.10?ab? 4.86?a? 5.63?a? 5.79?b???7.98?a? 8.93?a? 7.30?b? 7.35?a? 3.82?c???8.58?a? 6.30?a? TOPF???6.29?ab? 5.59?b? 4.34?a? 4.93?a???7.03?ab???9.85?a? 8.61?a???8.08?ab? 7.69?a???4.35?bc???8.06?a? 7.18?a? TOPR???5.70?ab? 5.61?b? 4.72?a? 5.14?a? 5.83?a???7.48?a? 8.04?a? 6.42?b? 6.23?a? 3.80?c???8.43?a? 6.59?a? ST8???7.29?ab? 8.40?a? 5.61?a? 6.39?a???7.39?ab? 10.09?a? 8.07?a???8.25?ab? 7.30?a???5.04?ab? 11.22?a? 6.49?a? STB? 7.97?a???6.95?ab? 4.54?a? 6.12?a? 6.18?b???9.24?a? 7.96?a???7.57?ab? 8.09?a? 5.54?a? 10.36?a? 7.19?a? CNTRL? 5.07?b???6.43?ab? 4.19?a? 4.99?a???6.74?ab???8.38?a? 7.33?a? 7.00?b? 7.40?a???4.17?bc???8.16?a? 6.27?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0?10),?CNTRL? unfertilized?control? ? ? ? ? 66 ? ? Table?18.?Ammonium?N?(mg?N?kg ?1 ?soil)?(NH 4 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2010,?Auburn,?AL.? N?? Source? Harvest?Date?(weeks?after?application)? ?? May?11?? (1)? May?17??? (2)? May?24???? (3)? June?1???? (4)? June?7???? (5)? June?14??? (6)? June?21??? (7)? June?28?? (8)? July?6????? (9)? July?12? (10)? July?19? (11)? July?27? (12)? UREA? 2.78?c? ????2.71?abc? 2.24?a? 1.66?a? 1.76?a? 6.94?a? 5.58?a? 4.55?a? 4.61?a? 0.29?b? 4.89?b? 5.93?a? MILORG? ????4.07?abc?????2.72?abc? 2.12?a? 2.21?a? 3.42?a? 7.38?a? 4.92?a? 2.56?a? 4.34?a???0.54?ab???6.23?ab? 5.27?a? NSS? 4.84?a? 4.29?a? 2.56?a? 1.82?a? 3.04?a? 6.78?a? 5.89?a? 4.41?a? 5.76?a? 0.97?a? 9.70?a? 4.66?a? NSSG???4.60?ab? ????2.91?abc? 3.02?a? 1.66?a? 2.60?a? 6.82?a? 4.70?a? 2.73?a? 4.06?a???0.61?ab???8.61?ab? 4.32?a? ST4? ????3.23?abc???2.09?bc? 2.42?a? 2.15?a? 2.14?a? 5.24?a? 3.89?a? 3.02?a? 4.62?a? 0.43?b???5.34?ab? 4.31?a? TOPF? ????3.64?abc? 2.04?c? 1.88?a? 1.51?a? 2.13?a? 5.80?a? 4.37?a? 2.94?a? 4.94?a???0.45?ab???5.09?ab? 5.28?a? TOPR???3.01?bc? 1.88?c? 2.49?a? 1.99?a? 1.89?a? 5.62?a? 4.41?a? 1.93?a? 4.08?a???0.63?ab???5.50?ab? 4.84?a? ST8? ????4.45?abc???3.68?ab? 3.06?a? 1.86?a? 2.50?a? 7.18?a? 5.36?a? 2.38?a? 4.73?a???0.55?ab???8.35?ab? 4.62?a? STB? ????3.44?abc? 1.84?c? 2.15?a? 2.03?a? 2.09?a? 6.49?a? 3.95?a? 2.86?a? 4.73?a???0.80?ab???6.87?ab? 5.42?a? CNTRL???3.09?bc? 1.65?c? 2.21?a? 1.83?a? 2.21?a? 6.13?a? 4.41?a? 3.16?a? 4.63?a???0.72?ab???5.97?ab? 4.62?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0?10),?CNTRL? unfertilized?control? ? ? ? ? 67 ? ? Table?19.?Nitrate?N?(mg?N?kg ?1 ?soil)?(NO 3 ?N)?(2M?KCl?extract)?soil?content?as?affected?by?N?source,?2010,?Auburn,?AL.? N? Source? Harvest?Date?(weeks?after?application)? ?? May?11? (1)? May?17? (2)? May?24?? (3)? June?1?? (4)? June?7??? (5)? June?14 ?? (6)? June?21? (7)? June?28???? (8)? July?6??? (9)? July?12??? (10)? July?19? (11)? July?27??? (12)? UREA? 3.34?b? 3.94?a? 2.96?a? 4.59?a???4.31?ab 1.62?a???4.13?ab ??5.28?ab???2.58?ab ????4.00?abc 2.68?a? 1.73?a? MILORG???2.63?bc? 3.79?a? 2.01?a? 3.31?a? 5.35?a? 2.34?a???3.69?ab ????4.85?abc ??2.27?ab 3.42?c? 2.79?a? 1.65?a? NSS? 3.23?b? 4.45?a? 1.99?a? 4.38?a???4.24?ab 1.61?a? 2.69?b? 3.40?c???2.24?ab ??3.65?bc? 3.13?a? 1.60?a? NSSG???3.11?bc? 5.18?a? 2.64?a? 4.59?a? 2.54?b? 2.79?a? 5.11?a? ????4.69?abc 3.31?a? ????3.78?abc 3.20?a? 1.67?a? ST4???2.78?bc? 5.01?a? 2.44?a? 3.48?a???3.65?ab 2.74?a? 5.03?a???4.27?bc???2.73?ab 3.39?c? 3.24?a? 1.99?a? TOPF???2.65?bc? 3.55?a? 2.46?a? 3.42?a? 4.90?a? 4.05?a???4.24?ab ??5.14?ab???2.75?ab ????3.90?abc 2.97?a? 1.90?a? TOPR???2.69?bc? 3.73?a? 2.23?a? 3.15?a???3.93?ab 1.85?a???3.63?ab ????4.49?abc 2.17?b? 3.17?c? 2.93?a? 1.76?a? ST8???2.84?bc? 4.73?a? 2.55?a? 4.53?a? 4.89?a? 2.91?a? 2.72?b? 5.87?a???2.57?ab ??4.49?ab? 2.86?a? 1.88?a? STB? 4.53?a? 5.11?a? 2.39?a? 4.08?a???4.09?ab 2.75?a???4.01?ab ????4.71?abc 3.36?a? 4.74?a? 3.49?a? 1.77?a? CNTRL? 1.87?c? 4.78?a? 1.98?a? 3.16?a???4.53?ab 2.25?a???2.92?ab ??3.84?bc???2.78?ab 3.45?c? 2.19?a? 1.66?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32? 0?10),?CNTRL?unfertilized?control? ? ? ? 68 ? ? Table?20.?Total?soil?N?((inorganic?+?organic)?g?N?kg ?1 ?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N????????? Source? Harvest?Date?(weeks?after?application)? ?? May?5???? (1)? May?12???? (2)? May?19? (3)? May?26? (4)? June?2?????? (5)? June?9??? (6)? June?16? (7)? June?23??? (8)? June?30? (9)? July?7??? (10)? July?14? (11)? July?21? (12)? UREA? 0.53?a? 0.39?a? 0.67?a? 0.46?a???0.41?ab? 0.58?a? 0.74?a? 0.89?a? 0.73?a? 0.71?b? 0.60?b? 0.70?a? MILORG? 0.29?a? 0.32?a? 0.68?a? 0.40?a???0.40?ab? 0.57?a? 0.72?a? 0.96?a? 0.72?a? 0.69?b???0.62?ab? 0.74?a? NSS? 0.58?a? 0.37?a? 0.66?a? 0.41?a???0.39?ab? 0.58?a? 0.76?a? 0.91?a? 0.79?a???0.82?ab???0.71?ab? 0.73?a? NSSG? 0.39?a? 0.31?a? 0.61?a? 0.44?a???0.42?ab? 0.54?a? 0.67?a? 0.97?a? 0.74?a? 0.91?a???0.70?ab? 0.74?a? ST4? 0.55?a? 0.35?a? 0.83?a? 0.47?a? 0.50?a? 0.76?a? 0.78?a? 1.00?a? 0.74?a???0.75?ab? 0.84?a? 0.66?a? TOPF? 0.77?a? 0.28?a? 0.67?a? 0.47?a???0.39?ab? 0.63?a? 0.77?a? 1.03?a? 0.68?a? 0.70?b???0.69?ab? 0.75?a? TOPR? 0.45?a? 0.43?a? 0.59?a? 0.45?a???0.41?ab? 0.51?a? 0.70?a? 1.01?a? 0.78?a???0.77?ab???0.63?ab? 0.70?a? CNTRL? 0.36?a? 0.38?a? 0.69?a? 0.44?a? 0.32?b? 0.56?a? 0.72?a? 0.98?a? 0.75?a? 0.73?b???0.64?ab? 0.72?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 69 ? ? Table?21.?Total?soil?N?((inorganic?+?organic)?g?N?kg ?1 ?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,Auburn,?AL.? N?????? Source? Harvest?Date?(weeks?after?application)? ? May?11? (1)? May?17??? (2)? May?24? (3)? June?1??? (4)? June?7??? (5)? June?14??? (6)? June?21??? (7)? June?28? (8)? July?6??? (9)? July?12? (10)? July?19? (11)? July?27?? (12)? UREA? 0.56?a? 0.40?a???1.02?ab 0.92?a? 0.93?a???0.85?bc? 0.66?a???0.97?ab 0.40?a? 0.12?a? 0.00?b???0.22?ab? MILORG? 0.65?a? 0.40?a???1.00?ab 0.88?a? 0.96?a? 1.03?a? 0.77?a???0.80?ab 0.30?a? 0.24?a???0.55?ab ??0.32?ab? NSS? 0.57?a? 0.48?a???1.01?ab 0.72?a? 0.89?a? 0.83?c? 0.76?a? 1.09?a? 0.34?a? 0.29?a? 0.42?a? 0.00?b? NSSG? 0.67?a? 0.58?a???0.81?ab 1.20?a? 0.93?a???0.95?abc? 0.78?a???0.84?ab 0.51?a? 0.22?a? 0.64?a???0.28?ab? ST4? 0.74?a? 0.64?a???1.06?ab 0.83?a? 1.00?a???0.93?abc? 0.66?a???1.04?ab 0.50?a? 0.32?a? 0.77?a???0.17?ab? TOPF? 0.56?a? 0.56?a???1.05?ab 0.98?a? 0.93?a???0.88?abc? 0.72?a???0.93?ab 0.51?a? 0.11?a? 0.34?a? 0.50?a? TOPR? 0.49?a? 0.37?a???0.97?ab 0.88?a? 1.01?a???0.87?abc? 0.45?a???0.76?ab 0.45?a? 0.21?a? 0.43?a???0.21?ab? ST8? 0.62?a? 0.51?a???1.00?ab 2.35?a? 1.04?a???0.90?abc? 0.64?a? 0.72?b? 0.63?a? 0.24?a? 0.57?a???0.16?ab? STB? 0.72?a? 0.57?a? 0.75?b? 0.97?a? 0.94?a? 1.02?a? 0.43?a???0.96?ab 0.34?a? 0.11?a? 0.43?b???0.32?ab? CNTRL? 0.53?a? 0.41?a? 1.15?a? 0.74?a? 0.93?a???1.00?ab? 0.62?a???0.96?ab 0.47?a? 0.09?a???0.41?ab ??0.22?ab? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation? at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts? Turf?Builder?(32?0?10),?CNTRL?unfertilized?control? ? ? ? 70 ? ? Table?22.?Soil?C?(g?C?kg ?1 ?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2009,?Auburn,?AL.? N???????? Source? Harvest?Date?(weeks?after?application)? ?? May?5??? (1)? May?12? (2)? May?19? (3)? May?26? (4)? June?2???? (5)? June?9??? (6)? June?16 ?? (7)? June?23??? (8)? June?30?? (9)? July?7??? (10)? July?14? (11)? July?21? (12)? UREA? 9.09?a? 8.18?a? 9.38?a? 6.90?a? 6.51?a???8.27?ab 7.55?a???9.53?a? ????8.94?ab ??7.23?ab? 6.61?b? 8.37?a? MILORG? 7.71?a? 8.31?a? 8.41?a? 6.68?a? 6.76?a? 7.90?b? 8.18?a? 10.70?a? ????8.74?ab ??7.73?ab???7.49?ab? 9.34?a? NSS? 8.62?a? 8.82?a? 8.12?a? 6.53?a? 6.42?a???8.36?ab 7.71?a? 10.50?a???10.36?ab ??8.94?ab? 8.55?a? 9.46?a? NSSG? 7.86?a? 8.67?a? 8.66?a? 7.16?a? 6.84?a???8.45?ab 6.93?a? 11.23?a? 10.51?a? 9.51?a???7.98?ab? 9.62?a? ST4? 8.12?a? 8.18?a? 7.63?a? 6.73?a? 7.16?a? 11.75?a? 8.44?a? 10.77?a???8.32?b???7.95?ab???7.63?ab? 7.98?a? TOPF? 8.70?a? 7.89?a? 8.12?a? 7.06?a? 6.77?a???8.98?ab 8.12?a? 11.86?a? ????8.45?ab 7.04?b???7.32?ab? 9.28?a? TOPR? 8.76?a? 7.98?a? 7.90?a? 7.92?a? 7.08?a? 7.34?b? 7.45?a? 11.90?a? ????9.86?ab ??7.53?ab???7.62?ab? 8.90?a? CNTRL? 8.40?a? 9.03?a? 9.29?a? 6.99?a? 6.06?a? 7.75?b? 7.58?a? 10.40?a? ????8.86?ab ??7.62?ab???7.77?ab? 8.52?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4? 6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 71 ? ? Table?23.?Soil?C?(g?C?per?kg?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?2010,Auburn,?AL.? N?????? Source? Harvest?Date?(weeks?after?application)? ? May?11???? (1)? May?17??? (2)? May?24??? (3)? June?1??? (4)? June?7??? (5)? June?14? (6)? June?21??? (7)? June?28? (8)? July?6???? (9)? July?12? (10)? July?19? (11)? July?27? (12)? UREA? 10.86?a???10.50?ab? 14.26?a? 11.88?a 10.30?a???12.28?ab 15.49?a? 15.58?a???9.52?a ??7.61?a ??7.05?a? ????8.88?ab MILORG? 11.30?a???10.50?ab? 11.78?a? 11.73?a 12.86?a? 13.73?a? 15.22?a???13.73?ab ??8.06?a ??9.38?a 12.86?a? ????9.31?ab NSS? 10.70?a???10.77?ab? 12.06?a???9.95?a? 11.36?a? 11.40?b? 14.00?a???15.13?ab 10.29?a 10.10?a ??11.52?ab ??6.25?b? NSSG? 12.21?a? 12.49?a? 12.32?a? 11.60?a 11.27?a???11.86?ab 16.19?a???14.18?ab 10.73?a ??8.66?a 14.16?a? ????7.93?ab ST4? 12.28?a? 12.57?a? 13.98?a? 11.11?a 12.16?a???11.83?ab 14.23?a? 15.53?a? 10.93?a 10.12?a 13.68?a? ????8.98?ab TOPF? 12.13?a???11.91?ab? 13.30?a? 10.61?a 11.70?a? 11.38?b? 14.81?a???15.35?ab ??9.71?a ??8.06?a ??10.86?ab 11.42?a? TOPR? 10.78?a???10.22?ab? 12.24?a? 10.96?a 12.75?a???12.65?ab 12.75?a???14.05?ab 10.06?a ??9.85?a 11.69?a? ????8.23?ab ST8? 11.78?a???11.11?ab? 10.95?a? 12.31?a 12.31?a???13.03?ab 13.48?a???15.20?ab 10.46?a ??9.48?a 12.99?a???7.58?b? STB? 12.22?a???11.82?ab? 10.71?a? 12.31?a 10.16?a???13.15?ab 12.67?a? 12.88?b???8.92?a ??7.99?a 12.22?a? ????9.83?ab CNTRL? 10.39?a???9.83?b? 13.90?a? 11.29?a 12.07?a???12.53?ab 12.65?a???13.23?ab ??8.99?a ??8.34?a ??11.22?ab ????7.78?ab ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=? 0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32? 0?10),?CNTRL?unfertilized?control? ? ? ? 72 ? ? Table?24.?Soil?microbial?biomass?(?g?C?per?g?soil)?of?hybrid?bermudagrass?as?affected?by?N?source,?27?July?2010,?Auburn,?AL.? N?????????????? Source? ?g?C?per?g?soil? ? UREA? 171.6?a? MILORG? 217.0?a? NSS? 154.4?a? NSSG? 241.8?a? ST4? 222.4?a? TOPF? 217.3?a? TOPR? 210.0?a? ST8? 181.7?a? STB? 214.4?a? CNTRL? 180.4?a? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means? separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),? ST4?Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),? STB?Scotts?Turf?Builder?(32?0?10),?CNTRL?unfertilized?control? ? ? ? 73 ? ? Table?25.?Weekly?maximum?and?minimum?temperatures?of?hybrid?bermudagrass,?2010,?Auburn,?Al.? Weeks?After?Application? soil????thatch?? ? ????? ? T min ??T max ??T min ??T max ? ???? ? ?C? ???? 1? 17.5??28.3??38.8??70.9? ???? 2? 18.3??28.7??60.6??68.3? ???? 3? 21.0??30.7??29.9??69.1? ???? 4? 22.1??31.1??38.3??66.6? ???? 5? 23.6??31.9??39.2??65.8? ???? 6? 24.4??34.4??36.1??68.3? ???? 7? 25.6??35.3??31.5??67.4? ???? 8? 27.9??34.9??27.1??66.6? ???? 9? 17.1??33.2??34.4??62.7? ???? 10? 26.3??31.9??19.8??66.6? ???? 11? 27.5??31.9??25.6??49.0? ???? 12? 27.1?? 32.8???26.0???59.2? ? ????? ?probe?inserted?at?5?cm?depth? ?probe?inserted?at?2.5?cm?depth ? ? ? 74 ? ? Table?26.?Root?and?shoot?measurements?(average?of?two?57?mm?diameter?cores)?of?hybrid?bermudagrass?as?affected?by?N?source,?21?July?2009,? Auburn,?AL.? N????????????? Source? ? root?weight??????? (g)? ? shoot?density?????????????? (shoots?per?core)? ? rhizome/stolon?weight?????? (g)? ? rhizome/stolon?diameter??????? (mm)? ? ??? ? UREA?? 0.78?a?? 102?a?? 5.7?a?? ?1.5?ab?? ??? ? MILORG?? 0.84?a?? 102?a?? 6.0?a?? 1.6?a?? ??? ? NSS?? 0.77?a? ? ????94?ab?? 6.0?a?? 1.3?b?? ??? ? NSSG?? 0.87?a?? 107?a?? 5.0?a?? ?1.6?ab?? ??? ? ST4??0.66?a? ? ????91?ab?? 5.0?a?? 1.6?a?? ??? ? TOPF?? 0.70?a? ? ????92?ab?? 5.0?a?? ?1.5?ab?? ??? ? TOPR?? 0.83?a?? ?99?a?? 6.0?a?? 1.6?a?? ??? ? CNTRL?? 0.84?a?? ?79?b?? 5.0?a?? ?1.5?ab?? ??? ? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? ? ? 75 ? ? Table?27.?Root?and?shoot?measurements?(averaged?of?two?57?mm?diameter?cores)?of?hybrid?bermudagrass?as?affected?by?N?source,? 2010,?Auburn,?AL.? N???????? Source? Harvest?Date?(weeks?after?application)? ? ?? root?weight?(g)??shoot?density?(shoots?per?core)??rhizome/stolon?diameter?(mm)?? ?? June?2???? (4)? July?6??? (9)? June?27?? (12)? ?? June?2????? (4)? July?6??? (9)? June?27??? (12)? ?? June?2??? (4)? July?6????? (9)? June?27??? (12)?? UREA? 8.3?a? 6.5?a? 5.3?b???170?a? 138?a? 140?a????1.4?ab? ????1.3?abc 1.2?a? ? MILORG? 7.6?a? 6.2?a? 7.7?a????159?ab? 138?a? 129?a? ?? ????1.3?abc ??1.2?bc? 1.2?a? ? NSS? 7.2?a? 5.8?a???5.9?ab????150?ab? 144?a? 132?a? ?? ????1.3?abc ??1.3?ab? 1.2?a? ? NSSG? 8.0?a? 5.6?a? 5.4?b????156?ab? 141?a? 128?a????1.2?bc? 1.1?c? 1.2?a? ? ST4? 7.7?a? 6.3?a???6.3?ab????141?ab? 167?a? 126?a? ?? ????1.3?abc ??1.1?bc? 1.3?a? ? TOPF? 7.0?a? 6.6?a???7.2?ab??? 133?b? 152?a? 135?a???1.1?c? 1.4?a? 1.1?a? ? TOPR? 8.4?a? 6.3?a???5.9?ab????130?ab? 133?a? 124?a? ?? ????1.3?abc ??1.2?bc? 1.2?a? ? ST8? 8.9?a? 5.9?a???6.7?ab????159?ab? 160?a? 136?a????1.4?ab???1.2?bc? 1.2?a? ? STB? 6.7?a? 5.2?a? 5.6?b????144?ab? 137?a? 134?a????1.4?ab? ????1.3?abc 1.3?a? ? CNTRL? 8.3?a? 5.8?a???6.9?ab????142?ab? 137?a? 114?a???1.5?a? ????1.2?abc 1.2?a? ? ??within?each?sampling?date?means?followed?by?the?same?letter?are?not?significantly?different?from?each?other?via?means?separation?at? ???=?0.05.? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4? Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts? Turf?Builder?(32?0?10),?CNTRL?unfertilized?control? ? ? ? ? ? 76 ? Table?28.?Laboratory?mineralization?study,?analysis?of?variance?table,?Auburn,?AL.? ? Effect? Degrees?of?Freedom? F?Value? P?>?F?Values? Day?0? Day?70? NH 4 ? Temp? 2? 3? 1.0? 0.5? 1.0? Trmt? 6? 118? 46.0? 0.0*? 0.0*? Temp?x?Trmt 12? 118? 4.8? 0.0*? 0.0*? ??????? NO 3 ? Temp? 2? 3? 0.5? 0.7? 0.6? Trmt? 6? 118? 3.7? 0.0*? 0.0*? Temp?x?Trmt 12? 118? 4.6? 0.0*? 0.0*? ??????? Total ? N ??? ?? ?? ?? ?? (NH 4 ? N ? + ? NO 3 ? N) ? Temp? 2? 3? 0.8? 0.5? 0.8? Trmt? 6? 118? 26.5? 0.0*? 0.0*? Temp?x?Trmt 12? 118? 1.2? 0.3? 0.0*? *denotes?a?significant?effect?at???=?0.05. ? ? ? 77 ? Table?29.?P?values?for?organic?fertilizer?treatments?used?in?mineralization?study,?Auburn,?AL.? ?? ? ? Adjusted?P?value??? ? N???? Source? %?recovery Std.?Err. NSS? NSSG? ST? TOPF? TOPR? UREA? Std.? Err.? LSD?0.05? 15?C ? MILORG? 37.3? 6.1? ???0.0* ???0.0*? ???0.0* ?0.2??1.0? ???0.0*? 2.77? 5.48? NSS? 62.3? 6.1? .??0.7 ????? ???0.0* ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? NSSG? 58.0? 6.1? .? .? ???0.0* ??????0.0*? ???0.0*? ???0.0*? 2.77? 5.48? ST4? 20.1? 6.1? .? .? .? ???0.0*? ???0.0*??1.0? 2.77? 5.48? TOPF? 30.6? 6.1? .? .? .? .??0.1? ???0.0*? 2.77? 5.48? TOPR? 38.2? 6.1? .? .? .? .? .? ???0.0*? 2.77? 5.48? UREA? 18.4? 6.1? .? .? .? .? .? .??? ? 25?C ? MILORG? 49.5? 6.1? ???0.0* ???0.0*? ???0.0* ???0.0*??0.7? ???0.0*? 2.77? 5.48? NSS? 66.5? 6.1? .? 0.5? ???0.0* ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? NSSG? 61.4? 6.1? .? .? ???0.0* ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? ST4? 16.6? 6.1? .? .? .? ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? TOPF? 38.7? 6.5? .? .? .? .??0.8? ???0.0*? 3.50? 6.93? TOPR? 43.9? 6.5? .? .? .? .? .? ???0.0*? 3.50? 6.93? UREA? 27.4? 6.1? .? .? .? .? .? .??? ? 35?C ? MILORG? 43.9? 6.1? ???0.0* ???0.0*? ???0.0* ???0.0*??0.4? ???0.0*? 2.77? 5.48? NSS? 60.1? 6.1? .??0.8? ???0.0* ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? NSSG? 56.2? 6.1? .? ?? ???0.0* ???0.0*? ???0.0*? ???0.0*? 2.77? 5.48? ST4? 31.7? 6.1? .??.??0.7??0.2??0.0? 2.77? 5.48? TOPF? 27.3? 6.1? .? .? .? .? ???0.0*??1.0? 2.77? 5.48? TOPR? 38.3? 6.1? .? .? .? .? .? ???0.0*? 2.77? 5.48? UREA? 29.9? 6.1??? ? ? .? .? .? .? .? *denotes?significant?effect?at???=?0.05? ?UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8? 3?5),?ST4?Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ? 78? ? Table?30.?Transition?day?and?percent?recovery?for?mineralization?study,?Auburn,?AL.? ? N?????????? Source ? ? ? ??15?C? 25?C? 35?C?? Days ? at ? transi tion ? UREA???7.4???5.6???5.4 MILORG???9.8???8.8???5.4?? NSS? 12.2???9.0???7.1 NSSG? 31.7? 10.7???8.3?? ST4???9.4???3.1???4.1 TOPF???5.2???9.2???7.3?? TOPR???8.0? 12.3???7.6 % ? recovery ?? ??? ? (inorganic ? N) ? ??? ?? ?? ?? at ? transition ? UREA? 15.3? 21.7? 24.1?? MILORG? 23.6? 28.4? 29.5 NSS? 40.0? 46.3? 45.0?? NSSG? 45.3? 40.4? 39.8 ST4? 12.8? 8.5? 21.2?? TOPF? 22.8? 23.5? 19.0 TOPR? 19.2? 25.3? 24.0?? % ? recovered ?? ??? ?? ?? ?? (total ? inorganic ? N) ? UREA? 18.4? 27.4? 29.9 MILORG? 37.3? 49.5? 43.9?? NSS? 62.3? 66.5? 60.1 NSSG? 58.0? 61.4? 56.2?? ST4? 20.1? 16.6? 31.7 TOPF? 30.6? 38.7? 27.3?? TOPR? 38.2? 43.9? 38.3 ?transition?point?is?the?intercept?of?two?predicted?models?of?mineralization? ??UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?NatureSafe?Starter?(5?6?6),?NSSG? Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2? 2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ? 79? ? ? Table?31.?Weekly?maximum?and?minimum?air?temperatures?for?incubation?study?(15?and?35?C),?2010.? ??15?C?Rep?2??35?C?Rep?1??35?C?Rep?2?? Weeks?After? Application? ?? T max ? T min ???T max ? T min ???T max ? T min ? ? 1??15.62? 12.55?? *? *??36.13? 29.90?? 2 15.62? 12.55? ?? *? *??35.27? 32.76?? 3??15.62? 12.55? ?? *? *??34.85? 34.01?? 4 15.62? 12.93? ?? 34.85? 34.01??35.27? 32.34?? 5??15.62? 12.93? ?? 34.85? 31.52??35.27? 32.34?? 6 15.62? 12.55? ?? 34.85? 32.34??35.27? 32.76?? 7??15.62? 12.93? ?? 34.85? 29.90??35.27? 28.70?? 8 15.62? 12.93? ?? 34.85? 29.50??35.27? 28.70?? 9??15.62? 12.93? ?? 34.85? 32.34??35.27? 27.91?? 10 15.62? 12.93? ?? 35.27? 34.01??35.27? 29.10?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ? *?missing?data;?all?25?C?and?15?C?rep?1?data?was?lost? ? ? ? 80 ? Figure?1.??Visual?color?rating?(1?to?9)?of?hybrid?bermudagrass?as?affected?by?N?source,?applied?on?April?27,?2009,?Auburn,?AL.? Vertical?bars?represent?the?standard?error.? 1 2 3 4 5 6 7 8 9 1 3 5 7 14 21 28 35 42 49 56 63 70 77 84 Days?After?Application Vi s u a l ? Co l o r ? (1 ? to ? 9) UREA MILORG NSS NSSG ST4 TOPF TOPR CNTRL ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6? 4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 81 ? Figure?2.??Visual?color?rating?(1?to?9)?of?hybrid?bermudagrass?as?affected?by?N?source,?applied?on?May?4,?2010,?Auburn,?AL.? ???Vertical?bars?represent?the?standard?error.? 1 2 3 4 5 6 7 8 9 1 3 5 7 14 21 28 35 42 49 56 63 70 77 84 Days?After?Application Vi s u a l ? Co l o r ? (1 ? to ? 9) UREA MILORG NSS NSSG ST4 TOPF TOPR ST8 STB CNTRL ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0? 10),?CNTRL?unfertilized?control? ? ? ? 82 ? Figure?3.??Colorimeter?reflectance?of?hybrid?bermudagrass?as?affected?by?N?source,?applied?on?April?27,?2009,?Auburn,?AL.? ??Vertical?bars?represent?the?standard?error.? 100 150 200 250 300 12345678910112 Weeks?After?Application Col o r i me te r ? ( r e f le ct a n ce ) UREA MILORG NSS NSSG ST4 TOPF TOPR CNTRL ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane??(4?6?4),? TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?CNTRL?unfertilized?control? ? ? ? 83 ? Figure?4.??Colorimeter?reflectance?of?hybrid?bermudagrass?as?affected?by?N?source,?applied?on?May?4,?2010,?Auburn,?AL.? ???Vertical?bars?represent?the?standard?error.? 200 250 300 350 400 450 12345678910112 Weeks?After?Application Col o r i me te r ? ( r e f le ct a n ce ) UREA MILORG NSS NSSG ST4 TOPF TOPR ST8 STB CNTRL ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2),?ST8?Sustane??(8?2?4),?STB?Scotts?Turf?Builder?(32?0? 10),?CNTRL?unfertilized?control? ? ? ? 84 ? Figure?5.??Correlation?between?visual?color?and?chlorophyll?meter?readings?as?affected?by?N?source,?2009,?Auburn,?AL.? y?=?28.6x?+?51.7 R 2 ?=?0.813 0 50 100 150 200 250 300 123456789 Visual?Color?Rating?(1?to?9) Co lo r i m e t e r ? ( r e f l e ct a n ce ) ? ? ? ? 85 ? Figure?6.??Correlation?between?visual?color?and?chlorophyll?meter?readings?as?affected?by?N?source,?2010,?Auburn,?AL.? y?=?19.1x?+?201.9 R2?=?0.429 0 50 100 150 200 250 300 350 400 450 123456789 Visual?Color?Rating?(1?to?9) Color i m e t e r ? ( r e f l e ct a n ce ) ? 86? ? ? Figure?7.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?urea?application?to?a?Marvyn? loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C?(bottom),?respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e r y ? (i n o r g a n i c ? N) ? *?Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted);?vertical?bar? (transition?day)? ? 87? ? ? Figure?8.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?Milorganite?application?to?a? Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C?(bottom),? respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e r y ? (i n o r g a n i c ? N) 0 10 20 30 40 50 60 70 % ? re c o v e r y ? (i n o r g a n i c ? N) 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ?*?Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted);?vertical?bar? (transition?day)? ? 88? ? ? Figure?9.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?NatureSafe?Starter? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e r y ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ? *?Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted),?vertical?bar? (transition?day)? ? 89? ? ? Figure?10.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?NatureSafe?StressGuard? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ? *Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted);?vertical?bar? (transition?day)? ? 90? ? ? Figure?11.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?Sustane??(4?6?4)? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e r y ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ? *?Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted),?vertical?bar? (transition?day)? ? 91? ? ? Figure?12.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?TOP?(fine?grade)?application? to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C?(bottom),? respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e r y ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ? *Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted);?vertical?bar? (transition?day)? ? 92? ? ? ?Figure?13.??Cumulative?inorganic?N?(NH 4 ?N?and?NO 3 ?N)?recovery?from?a?TOP?(regular?grade)? application?to?a?Marvyn?loamy?sand?with?soil?temperatures?at?15?(top),?25?(middle),?and?35?C? (bottom),?respectively.? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 % ? re c o v e ry ? (i n o r g a n i c ? N) ? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days?After?Application % ? re c o v e ry ? (i n o r g a n i c ? N) ? *Solid?diamond?(NH 4 ?N);?open?diamond?(NO 3 ?N);?solid?line?(NH 4 ?N?predicted);?dashed?line?(NO 3 ?N? predicted);?open?triangle?(total?inorganic?N);?dotted?line?(total?inorganic?N?predicted);?vertical?bar? (transition?day)? ? ? ? 93 Figure?14.??Percent?of?inorganic?N?(NH 4 ?N??+NO 3 ?N)?recovery?from?organic?fertilizer?sources?applied?to?a?Marvyn?loamy?sand?incubated?at? 15?C,?2009,?Auburn,?AL.?? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days % ? re c o v e ry ? (p r e d i c t e d ? tot a l ? N) UREA MILORG NSS NSSG ST TOPF TOPR ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?NatureSafe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ? ? ? 94 Figure?15.??Percent?of?inorganic?N?(NO 3 ?N?+?NH 4 ?N)?recovery?from?organic?fertilizer?sources?applied?to?a?Marvyn?loamy?sand?incubated?at? 25?C,?2009?and?2010,?Auburn,?AL.? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days % ? re co v e ry ? (p r e d i c t e d ? tot a l ? N) UREA MILORG NSS NSSG ST TOPF TOPR ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ? ? ? 95 Figure?16.??Percent?of?inorganic?N?(NO 3 ?N?+?NH 4 ?N)?recovery?from?organic?fertilizer?sources?applied?to?a?Marvyn?loamy?sand?incubated?at? 35?C,?2009?ad?2010,?Auburn,?AL.? 0 10 20 30 40 50 60 70 0 7 14 21 28 35 42 49 56 63 70 Days % ? re co v e ry ? (p r e d i c t e d ? to t a l ? N) UREA MILORG NSS NSSG ST TOPF TOPR ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ? ? ? 96 Figure?17.??Day?70?percent?recovery?of?inorganic?N?(NH 4 ?N?+?NO 3 ?N)?from?organic?fertilizers?applied?to?a?Marvyn?loamy?sand?at?15,?25,?and? 35?C,?respectively.? ? *UREA?Urea?(46?0?0),?MILORG?Milorganite?(6?2?0),?NSS?Nature?Safe?Starter?(5?6?6),?NSSG?Nature?Safe?StressGuard?(8?3?5),?ST4?Sustane?? (4?6?4),?TOPF?Top?Organic?Fine?Grade?(4?2?2),?TOPR?Top?Organic?Regular?Grade?(4?2?2)? ?