Comparison of Tillage Treatments on Greenhouse Gas Fluxes in Established Winter Wheat Production.

Tillage is commonly used to control weeds and prepare fields for planting.  Repeated tillage can result in soil drying, sudden bursts of mineralized carbon and nitrogen from soil organic matter, and alterations in soil microbial communities. The effects of tillage on winter wheat cropping systems and parameters listed above is not well understood in the Southern Plains. This study was conducted in July, 2015 at the USDA-ARS Grazinglands Research Laboratory, El Reno, Oklahoma in winter wheat sites where chisel plow, vertical tillage tool and control were compared. The main objective was to determine the impact of chisel plow and vertical tillage tool use on soil priming of carbon and nitrogen cycling and greenhouse gas (GHG) flux in winter wheat production. Soil and GHG samples were taken over 196 hours post plowing. Results indicate that carbon dioxide and nitrous oxide emissions are greatest from chisel plow use, followed by vertical tillage tool. A pulse of soil labile carbon and nitrogen can be seen as early as 3 hours post tillage in both chisel and vertical tillage tool treatments.  Both treatments had greater greenhouse gas flux compared to the no-till control. Knowledge of how different tillage practices alter soil priming and GHG emissions will help to establish sustainable management practices and improve ecosystem services, while reducing input cost.