Evaluation of a Novel Poultry-Derived Fertilizer

Abstract

Poultry litter, a common soil amendment, can be applied to soils as a plant nutrient source. Due to a balanced N: P ratio, applying poultry liter based on N rates may result in an overapplication of phosphorous which leads to eutrophication within aquatic environments. To reduce contamination risks, poultry litter can be altered through several different processes, such as anaerobic or aerobic digestion, and can be pelletized for a more uniform product distribution. In a novel fertilizer produced through this method, assessments were conducted to determine both chemical and physical product quality and application results when applied to a variety of crops. Product assessments were made of a proprietary process which combines aerobic digestion and ammonification to physically and chemically alter poultry litter. Through this process, standard poultry litter is transformed from a 1.5-1-1.5 N-P-K chemical formulation to a 11.5-1-1.5 N-P-K granulated product (C&G fertilizer). Nutrient release rates were investigated using a soil incubation test and a rapid water incubation test. Nutrient release rates in soil were evaluated at a 0.89 kg m3 rate (C&G, Synthetic, or Poultry Litter) with soil maintained at 0.3 cm3/cm3 volumetric water content at 30 C over a 55-day period. Rapid water incubation was conducted by adding one gram of fertilizer (C&G, Synthetic, or Osmocote) to 100 mL of water for 24-hour period. Electric conductivity was monitored to evaluate nutrient release over time. In soil, significant and increasing quantities of potassium, ammonium, and nitrate were released in the first six days of incubation for C&G. After six days, nitrate and potassium continue to increase while phosphorus and ammonium plateaued in release. In plant assays, three crops were grown using four fertilizer treatments at four rates. The treatments were Synthetic uncoated fertilizer, C&G, a nutrient even blend (C&G + Synthetic), and Poultry litter. Fertilizers were applied on a N basis of at the rates 0 kg m3, 0.44 kg m3, 0.89 kg m3, and 1.78 kg m3. C&G preformed similarly to a synthetic fertilizer across pH & EC sampling, growth indices and nutrient tissue analysis. Final results suggest the C&G fertilizer may be utilized similarly to synthetic, uncoated fertilizers for quick nutrient release.