Enhanced Efficiency Liquid Nitrogen Fertilizer Management for Corn Production

Abstract

Claypan soils have a high potential for N loss, which can lower corn (Zea mays L.) yields. Field research was conducted from 2011 to 2013 in Northeast Missouri to determine corn yield, plant population, and grain quality response to N application timings (fall vs. spring) and five N sources/placements at two different N rates (84 and 168 kg·N·ha-1) on a poorly drained claypan soil. The five N source/placement systems were no-till (NT)/surface broadcast urea ammonium nitrate (UAN) (Surface UAN) or strip-till (ST)/deep banded UAN (deep UAN), NT/surface broadcast UAN plus Nitamin Nfusion (surface NF) or ST/deep banded UAN plus Nitamin Nfusion (deep NF), and ST/deep banded anhydrous ammonia (AA) (deep AA). The field trial was a split-plot randomized complete block design with four replications. Deep UAN with a fall N application produced the highest grain yield (8.12 to 9.12 Mg·ha-1) at 84 and 168 kg·N·ha-1, but it was less effective with a spring application in 2011. Fall deep AA produced the lowest grain yields (5.97 and 6.8 Mg·ha-1) in 2013 at 84 and 168 kg·N·ha-1 potentially due to wet soil conditions at the time of application. Warmer and wetter soil conditions during April-May of 2013 resulted in relatively higher grain yields compared to cooler and drier soil conditions in 2011 with all spring-applied N source/placement treatments. Extreme drought in the 2012 growing season resulted in poor corn growth. Farmers may need to consider fall N applications on claypan soils because spring N application might be riskier since corn grain yield was generally greater than or equal to spring-applied treatments.