Biochar Effect On Water And Carbon Fluxes Between Cropland And Atmosphere: A Sensitivity Analysis Using The Community Land Model
Presenter: Sabrina Wilson1
Co-Author(s): -
Advisor(s): Dr. Yang Song
1Department of Hydrology and Atmospheric Sciences, University of Arizona
Biochar amendment is a soil health mitigation technique that has been proposed to provide positive impacts on greenhouse gas emissions and carbon sequestration. Biochar is composed of long chains of fused aromatic rings, therefore highly recalcitrant. Biochar’s multiple porous structures and larger surface area change soil moisture dynamics and make it easily adsorb other soil organic matter (SOM) and microbial enzymes, leading to the decreased accessibility of SOM by microbial communities. To date, there is still a lack of clear understanding about the effect of biochar addition on soil chemical and physical processes and the consequent impact on land-climate interactions. To address this knowledge gap, we incorporated biochar’s effects into the Community Land Model (CLM5.0) by parameterizing biochar as two distinct new pools – a recalcitrant lignin-like compound and a labile metabolic compound. The model will be calibrated using data from two corn-growing field sites – Boone County, Iowa, and Aurora, New York. We conducted a sensitivity analysis on how biochar addition affects crop yield, net ecosystem exchange (NEE), evapotranspiration (ET, and water use efficiency (WUE) by running the model under four different treatments: nitrogen fertilizer, biochar, biochar and nitrogen fertilizer, and control (no amendment).