Effect of Seeding Distance from Subsurface Banded Poultry Litter on Corn Yield and Leaf Nitrogen in a Conservation Tillage System.

Poultry litter is a nutrient dense soil amendment and is generated in large volumes throughout the southeastern USA where extensive row crop production, such as corn (Zea Mays L.) occurs. However, extensive surface poultry litter applications have resulted in ammonia losses to atmosphere and water systems. Therefore, research objectives were to determine optimum corn planting distance from subsurface-applied poultry litter bands that maximizes plant N uptake and plant productivity under both rainfed and irrigated conditions. This experiment was conducted as a split-block in Booneville, AR in 2016. Irrigation was the whole block and soil amendments the split-block, which included planting corn 13, 25.4, and 38-cm from sub-banded poultry litter and controls being represented as surface applied poultry litter, inorganic-N (all received equivalent N, 168 kg ha^-1), and 0 kg N ha^-1. Chlorophyll readings indicated surface applications of poultry litter and inorganic fertilizers resulted in greater leaf greenness, which was not different than 13-cm bands 60 days after planting (P<0.05). Banding distance had no impact on corn silage yields, however, the 25.4 and the 38-cm sub-surface treatments were not different than the inorganic fertilizer treatment, with the surface litter applications having lowest yields (P<0.05). Similarly, grain starch did not differ between inorganic fertilizer and poultry litter sub-surface applications. In addition, irrigation had no impact on silage yield, crude protein, or acid detergent fiber, but had a positive impact on silage neutral detergent fiber. Results suggest that sub-surface banding poultry litter >13-cm from corn rows may be a viable replacement for inorganic fertilizers, particularly in organic production systems in the southeast.