Incidence of greenhouse gas emissions from soils under different corn management practices

Management practices such as no-tillage and improved fertilizer management have the potential to improve corn yield and ultimately reduce greenhouse gas emissions from soils. A two year field scale study was conducted to evaluate the effects of various management practices on corn yield, CO2 and N2O emissions from soil. The study was conducted at Tennessee State University Agricultural Research and Demonstration center in Nashville, TN. The management practices included NT-URAN, NT-inhibitor, NT-biochar, NT-litter, NT-split fertilizer and CT-URAN. An equivalent of 217 kg N ha −1 fertilizer was applied to each of the experimental plots. The study was a randomized complete block design with four replications. The results showed that fertilizer management had no significant effect on corn yield. No-till (NT-URAN, NT-litter and NT-inhibitor) plots significantly increased corn yield compared to the conventional tillage (CT-URAN). Similarly, nitrous oxide flux was significantly influenced by no-tillage as well as fertilizer management practices; with the highest cumulative N2O (10.21 kg N2O ha-1), released from soil occurring in the CT-URAN treatment and less N2O emissions in the no-tillage management practices. N2O was especially less in the NT-inhibitor (3.57 kg N2O ha-1), NT-biochar (2.06 kg N2O ha-1) and the NT-split fertilizer (2.81 kg N2O ha-1) treatments. However, soil CO2 flux showed a contrasting result to N2O emission with CT-URAN plots exhibiting the lowest CO2 release of 12601.99 kg CO2 ha-1. The CT-URAN value was significantly different from NT-URAN and NT-litter of 14472.05 kg CO2 ha -1 and 15216.54 kg CO2 ha-1 respectively. The controlling factor for soil N2O emissions tends to be moisture while CO2 emission was temperature