The Nitrogen Fertilizer Value of Preplant-Incorporated Poultry Litter for Flood-Irrigated Rice

Poultry litter contains an abundance of nitrogen (N) and has been used to fertilize pastures and forage crops in western Arkansas for a number of years. The objective of this study was to determine the N-fertilizer value of preplant-incorporated fresh and pelletized litter in comparison to urea fertilizer applied before flooding rice at the fiveleaf stage. Studies were conducted on two silt loams and one clay soil in 2003. Litter was preplant-incorporated at rates of 0, 30, 60, 120, 180, and 240 lb total-N/acre and compared with urea applied preflood at 0 to 150 lb N/acre for silt loam soils and 0 to 250 lb N/acre for the clay soil. Rice N content and grain yield were used to estimate the value of litter as a N fertilizer source. Fresh and pelletized litter behaved similarly with both litter sources being less efficient N fertilizers when compared with urea. Maximum N uptake and rice yield were produced only when urea-N was applied at rates from 90 to 150 lb N/acre for silt loam soils and 200 to 250 lb N/acre for the clay soil. Averaged across litter-N application rates, rice recovered between 0 and 10% of litter-N by 0.5-in. internode elongation (IE) and 5 to 25% of litter-N by early heading compared to >40% of urea-N.