Water-conscious management strategies reduce per-yield irrigation and soil emissions of CO2, N2O, and NO in high-temperature forage cropping systems

Agricultural soils are important sources of greenhouse gases carbon dioxide (CO 2 ) and nitrous oxide (N O), as well nitric (NO), a precursor to tropospheric ozone. Management approaches that constrain these emissions can limit future warming improve regional air quality, especially in high-temperature agroecosystems where soil high. Subsurface drip irrigation is promising management solution via targeted rhizosphere access water nitrogenous fertilizers. In complementary field studies southern California, we compared per-yield surface- drip-irrigated plots growing alfalfa ( Medicago sativa L.) sudangrass Sorghum bicolor ssp. Sudanese), two forage crops with differing fertilizer requirements. For each study, monitored temperature, moisture, emission responses both spring summer using custom automated chamber array recorded measurements every 30 minutes. We found that, furrow irrigation, increased hay yield by 6% CO 9% while it decreased demand 49%, N O 59%, NO 49%. alfalfa, 7% decreasing 1%, 38%, 20%. crops, differences between types were strongest months, when high temperatures produced large pulses following flood relative small irrigation. As agriculture intensifies warmer climates, implementation subsurface help reduce the affect Earth’s climate quality. • Irrigation induced , O, from agricultural soils. reduced up 62%. The reductions for sudangrass. Drip flood, weakened seasonal increases emissions.