Tuesday, November 14, 2006 - 3:10 PM

Impact of Binding Agent and Dicyandiamide on Nitrogen-Fortified Granulated Poultry Litter and Biosolid Fertilizers.

Mark Reiter1, Tommy C. Daniel2, Robert G. Hinkle3, Nathan A. Slaton2, and Richard J. Norman2. (1) University of Arkansas, University of Arkansas, Plant Science Building 115, Fayetteville, AR 72701, (2) Univ of Arkansas, Plant Science Bldg 115, Fayetteville, AR 72701, (3) Mars Mineral Inc., P.O. Box 719, Mars, PA 16046

Alternative uses for poultry litter (PL) and biosolids (BS) are needed to enhance their value as a fertilizer source and improve the economics of their transport out of areas of nutrient surplus. The overall goal of this project was to convert PL and BS into a N-fortified granular fertilizer and evaluate the developed products utility as fertilizers. The objective of this study was to compare the influence of binding agent and dicyandiamide (DCD) on P and N release from the developed fertilizers. Poultry litter, BS, urea,  and DCD were used to develop four granulated-fertilizers which contained about 14% N, 1.7% P, and 3.3 % K including PL + urea (PLU), PLU + DCD (PLUDCD), PLU + BS (PLUB), and PLUB + DCD (PLUBDCD)] through agglomeration using a pin mixer. Each product was bound with lignosulfonate (LS), urea formaldehyde (UF), or water (WR) producing 12 different fertilizers. Soluble reactive P (SRP) was higher in all granulated products compared to fresh PL and BS during a water shake study. Soluble reactive P was released from granules bound with binding agents in the order: WR > LS > UF. During a 112 d incubation study, UF was not added in sufficient quantities to reduce nitrification compared to WR and LS. Nitrification did not occur in significant amounts when DCD was added until 56 d after application compared to 7 d in non-DCD fertilizers. Depending on additives, fortified granules can be produced for $0.71 to $1.15 kg N-1, similar to commercially available urea ($0.73 kg N-1). Granulation of PL and BS with urea and a nitrification inhibitor additive may be a viable alternative for fertilizer production.