Poultry Litter Ash As a Phosphorus Source for Corn.

As the expanding world population places pressure on the poultry industry to meet consumption demands, heightened poultry litter (PL) production increases volumes for land application. Repeated PL applications within localized distances of poultry operations creates nutrient concentrated areas posing a threat to ecosystems. Poultry litter ash (PLA), a co-product from manure-to-energy systems, is a promising solution addressing: transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source. The overarching project goal is to prove or disprove PLA as a comparable fertilizer. Thermo-conversion systems alter PLA nutrient solubility; therefore, the first objective is to determine solubility fractions of four PLA (Fluidized Bed Bulk, Combustion Mix, Fluidized Bed Fly, and Ash Coated Urea) and P fertilizers (poultry litter and triple super phosphate). Phosphorus sources were extracted sequentially using deionized water, NaHCO3, NaOH, HCl, and finally acid digested with HNO3 followed by analysis via ICP-AES. Water extraction represented soluble P (Ps%) whereas NaHCO3 signified labile inorganic P (Pi%). Phosphorus extracted by NaOH and HCl is categorized as non-labile inorganic or bound P (Pb%). The second objective is to compare nutrient availability of phosphorus (P) of PLA with industry standard P fertilizers and subsequent effect on corn yield. Experimental design included 13 fertilizer treatments arranged in a two factor randomized complete block design with source and rates as factors in a low P environment. Overall, nutrient solubility and plant availability is paramount for evaluating PLA derived co-products as grain fertilizers.