Quantifying Soil N₂O Emissions from Agricultural Lands

At University of Illinois at Urbana-Champaign, I completed multiple projects aimed to improve the quantification of soil N₂O emissions. At the broad scale, a process-based model (i.e., surrogate Century model) was utilized to estimate U.S. county-level soil N₂O emissions from corn fields under different climate and management scenarios. To enhance modeling performance, a data fusion approach was developed to derive county-level crop-specific fertilizer nitrogen (N) input dataset as model inputs. Additionally, a remote sensing and site covariate-based modeling approach was established to estimate cover crop N credits. Furthermore, the modeling scheme was improved by carrying out spatial validation using survey and meta-summary databases. At the local scale, field experiments were conducted to measure N₂O fluxes within different field management zones delineated with a digital soil mapping approach. Both positive and negative fluxes were observed from the field measures obtained from organic corn fields. Future research is planned to gain deeper insights into the underlying mechanisms responsible for these flux variations from diversified cropping systems.