Biochar's Ability to Reduce Greenhouse Gas Emissions and Sequester Carbon Under Varying Irrigation Regimes for Fertilized Corn Cropping Systems.

To curb the exponential rise in greenhouse gas (GHG; CO₂, N₂O and CH₄) emissions from the agricultural sector, particularly nitrous oxide (N₂O), farmers must seek practices that maximize soil carbon (C) sequestration, improve nitrogen (N) use efficiency and decrease N loss to the environment. Biochar soil amendments have been shown to sequester C, mobilize N and decrease soil N₂O production in soils under both laboratory and field experiments. Additional research is necessary to understand the biogeochemical processes occurring in biochar amended soils under field conditions, particularly under different soil moisture regimes. We will report results from a study where GHG emissions and soil C sequestration are measured in a fertilized corn cropping system across three different irrigation regimes (full irrigation, temporally limited irrigation and 50% deficit irrigation). This study employs a comprehensive GHG sampling protocol to capture both temporal and spatial variability in GHG emissions by combining dynamic cavity ring down spectroscopy measurements using automatic chambers with traditional gas chromatography measurements using static chambers. Results of this field study will be analyzed to better quantify relationships between GHG emissions and soil moisture and the impacts of biochar treatments on such relationships.