Lateral Spacing of Subsurface Poultry Litter Bands - Impact on Nitrous Oxide Emission.

Poultry litter (PL) as a nutrient source in no-till (NT) corn cropping system is generally land applied by surface broadcast, which can potentially lead to nitrogen (N) losses via nitrous oxide (N₂O) emission and ammonia (NH₃) volatilization.  A new application method was developed for forage cropping systems that allows subsurface banding of PL with minimal soil disturbance to conserve N. The objectives of this study were to determine if adjusting PL lateral subsurface band placement in relation to corn rows can affect NT corn yield and nitrous oxide emissions.  A two year field experiment was initiated May 2014 and treatments consisted of an untreated control (UTC), 32% urea ammonium nitrate surface banded (UAN), PL surface broadcast (PLBr), and 3 subsurface banded PL treatments.  The subsurface PL treatments consisted of 1 (PLSub1), 2 (PLSub2), or 3 (PLSub3) lateral bands in the inter-corn row area.  Treatments receiving N amendments were applied at the rate of 180 kg N ha^-1 each spring prior to corn planting.  Cumulative N₂O emissions did not vary among treatments receiving a N source in 2014.  However, in 2015, results indicated that PLSub1 and PLSub2 had cumulative N₂O emissions significantly lower than PLBr and statistically the same as UTC.  There was no significant difference in 2014 corn grain yields among the subsurface PL treatments however PLSub2 resulted in significantly higher grain yields than PLBr.  These results suggest that subsurface banding PL can conserve N and increase no-till corn grain yield over traditional surface broadcast PL.