Cotton Response to Urea and Organic Sources of Nitrogen

In recent years, unstable synthetic fertilizer prices coupled with desire for improving soil quality have rekindled interests in using various high organic matter byproducts as alternative N fertilizer sources for cotton in Arkansas. The specific objective of this project was to evaluate cotton yield response to fresh poultry litter (FPL), pelleted poultry litter (PPL) and a heat dried pelleted biosolids under soil and cropping systems of Arkansas. Two replicated field experiments were conducted in 2008 and 2009 on two soils typically used for cotton production in eastern Arkansas. Both studies were arranged as a randomized complete block design with a factorial arrangement of four N-fertilizer sources (FPL, PPL, TCO and urea) and five N rates plus a no N control. Each organic N source was applied based on the total N analysis. In 2008 the N source × N rate interaction had no significant influence on a seedcotton yield and averaged across N sources, N rates significantly increased seedcotton yields. Averaged across all N sources, seedcotton yields ranged from 1228 to 3279 lb/acre and increased numerically and often significantly with increasing N-rate. The results of the 2008 study suggest that seed cotton yields in eastern Arkansas can be increased by application of organic and inorganic sources of N. We will evaluate the reproducibility of these results by addition of the data from 2009 field season and discuss the implications of these findings for integrating organic sources of N into the overall N management for cotton production in Arkansas.