Impact of Conservation Management Practices on Greenhouse Gas Emissions on the Semiarid, Intensively Cropped Region of the Texas High Plain.

Agriculture is a leading source of the greenhouse gasses (GHGs) carbon dioxide, methane, and nitrous oxide, as well as ammonia; however, strides have been made to change agriculture from a source to a sink of GHGs through innovative cropping management practices including reduced tillage, cover cropping, and improved fertilization.  These management practices have been implemented on cotton production systems, but their impact on GHGs have not been evaluated on the Texas High Plains (THP) where monitoring environmental quality of GHG emissions while balancing limited water resources and soil’s productive capacity is a difficult challenge for agriculturalists and researchers.  This study aimed to evaluate the GHG emissions from cotton production systems treated with varying tillage, cover crops, and fertilizer application rates and timings.  There were three tillage systems: no-till with a wheat cover, no-till, and conventional tillage.  Nitrogen (N) fertilizer was applied at two different rates:100 lbs/acre and 150 lbs/acr, and at different timings: 100% preplant, 100% side-dressed, 40% preplant and 60% side-dressed, or 100% preplant with a N stabilizer.  GHG emissions were evaluated using a portable Fourier Transform Infrared (FTIR) multi-gas analyzer.  Discussion will include the impact of tillage, cover crops, and N fertilizer timing, source, and placement on GHG emissions and ammonia.