CO2, N2O and CH4 Fluxes from Agricultural Soils Under Corn (Zea mays L) Production.

Agricultural soils have the tendency to release significant amount of CO₂, N₂O and CH₄ into the atmosphere as greenhouse gasses. Our understanding of the mitigation of greenhouse gas (GHG) emissions from agricultural soils is still unclear. As such a three-year (2012-2014) field scale study  was conducted at Tennessee State University Agricultural Research and Demonstration center to evaluate the effects of agricultural management practices on CO₂, N₂O and CH₄ fluxes from soil. Corn was used as the test crop. Six URAN liquid fertilizer treatments were applied as follows:  1) URAN, two applications; 2)  URAN, four applications; 3) URAN + denitrification inhibitor; 4) URAN + chicken litter in no-till plots; 5) URAN  in  conventional plots and 6)  URAN + biochar. Each soil treatment was replicated four times. Soil CO₂, N₂O and CH₄ fluxes were measured 2-5 times a month during the corn growing season using closed chamber method and soil moisture and temperature was taken in-situ. Preliminary data indicate that CO₂ and N₂O fluxes exhibit significant seasonal variation during the experimental period. The seasonal dynamics of soil CO₂ flux was primarily controlled by soil temperature; while soil N₂O flux was controlled by soil moisture. N₂O and CO₂ fluxes were significantly influenced by the agricultural practices. Variation in N₂O emission among the treatments was positively correlated with soil moisture. All treatments exhibited minor sinks for CH₄ flux; with no significant differences among the treatments.