The long-term goal of this project is to improve our understanding of biochar as a potential tool in NOx mitigation from agricultural soils. Despite promising potential, there are few studies that measure how biochar influences soil NOx emissions. To address this research gap, I propose a 2-year field trial at an almond orchard in California's Central Valley where I will measure soil NOx emissions following the application of two different rates of biochar produced from locally available almond prunings and almond shells. The long-term goal will be achieved by completing the following supporting objectives:1.) Identify the optimal biochar type and application rate for minimizing NOx emissions.2.) Investigate the biological mechanisms through which biochar influences NOx emissions.