Nitrous Oxide Emissions From Agriculture: Sources, Sinks, and Mitigation.

Nitrous oxide (N₂O) emissions contribute about one third of the total greenhouse gas (GHG) emissions from California’s agricultural sector. Relatively little California specific data exists on N₂O emissions from agriculture and how agricultural management practices can affect N₂O emissions, making modeling and predictions difficult. Furthermore, N₂O pathways, including sinks as well as sources, are not well understood. Nine treatments were examined including five fertilizer rates ranging from 0 kg/ha N to 337 kg/ha N, two fertilizer sources, UAN vs. Aqua Ammonia, a fertilizer efficiency enhancer, Agrotain, 1 fertilizer band vs. two fertilizer bands, and drip irrigation vs. furrow irrigation in a corn field. Seasonal fluxes from each treatment will be analyzed and practices that reduce emissions will be identified. Future research will include greenhouse experiments examing N₂O absorption and metabolism by the plant canopy to better understand N₂O sinks.