Cotton Lint Yield Improvement Attributed to Residual Effect of Repeated Poultry Litter Application

Abstract

The magnitude of soil nutrients derived from poultry litter that carryover to succeeding seasons and the possibility to decrease litter rates applied to soils with only a few years of application history is not well understood. The objective of this research was to determine and quantify the potential carryover effect of moderate broiler litter fertilization rates on cotton (Gossypium hirsutum L.) lint yield in subsequent years. Cotton was fertilized with 0, 2.2, 4.5, 6.7 Mg ha−1 yr−1 broiler litter, 4.5 Mg ha−1 yr−1 litter plus 67 kg N ha−1 yr−1 as urea ammonium nitrate (UAN), or with 135 kg N ha−1 yr−1 as UAN (farm standard, Std) on a private farm under conventional till in Mississippi in 2002–2007. In 2005, each plot was divided into two equal subunits and one‐half continued to receive the same fertilization treatment and the other half was not fertilized in 2005 and the subsequent 2 yr. The results showed the 6.7 Mg ha−1 litter fertilization did not supply sufficient fertilization for optimum lint yield during the first 3 yr (2002–2004). But, lint yield of this treatment equaled that of the Std in the last 3 yr (2005–2007), suggesting a cumulative litter carryover in 2002–2004 was sufficient to meet the fertilization deficit. The results overall show that repeated litter application for a few years under conventional till management builds the nutrient pool gradually and that the rate of litter application might be reduced in subsequent years while maintaining optimum lint yield.