Subsurface Band Placement of Pelletized Poultry Litter to Cotton on Soil Quality Indicators.

Poultry litter is generally land applied as surface broadcast which exposes litter-derived nutrients to potential loss. Placing litter in narrow bands below the soil surface may help mitigate such losses while making more of the nutrients available for the crop and may improve soil quality. The effectiveness of subsurface band placement of pelletized poultry litter (PPL) to row crops on soil quality indicators has not been well documented. This study determined the effects of sub-surface band placement of PPL to cotton for four years on soil chemical and microbial indicators in Marietta loam (Fine-loamy, siliceous, active, thermic Fluvaquentic Eutrudepts) soil. Experimental design was a randomized complete block with three treatments replicated four times. Treatments included 6.7 Mg PPL ha^-1, 140 kg N ha^-1 as urea ammonium nitrate (UAN solution) applied in split, 56 kg ha^-1 at planting and 84 kg ha^-1 at squaring, and unfertilized control. Repeatedly applying PPL in spring 2010 – 2013 increased soil P, total N, and total C from the base line of 0.063, 0.45, and 11.1 g kg^-1 to 0.117, 0.74, and 13.4 g kg^-1, respectively, in the 0-15 cm depth. No difference in residual NO₃-N was obtained between PPL and control treatments. However, residual NO₃-N was substantially increased by applying inorganic fertilizer-N, indicating low crop N use potential and majority of N applied at planting leached beyond the root zone due to very limited root growth at early growth stage. Application of PPL increased soil dehydrogenase activity and cephalothin-resistant heterotrophic plate count bacteria. Subsurface band placement of PPL appeared to be very useful in enhancing cotton lint yield as a result of improved soil quality indicators.