Biotic and Abiotic Factors Controlling Nitrous Oxide Emissions from an Agricultural Soil In Controlled Environment Chambers Using Continuous Monitoring.

Nitrous oxide is a greenhouse gas 300 times more potent than carbon dioxide at trapping heat. Atmospheric levels have been steadily rising over the past 30 years, with agricultural soil management the major anthropogenic contributor in the United States.  Studies have measured periodic nitrous oxide emissions from field soils, but factors controlling the timing and amounts of emissions remain obscure.  In our studies, novel plant growth systems held in controlled environment chambers were used to precisely control the aerial and soil environments.  It was possible to determine  time lines of nitrous oxide release from soils after adjustments in fertilization, carbon substrate availability, soil water status, soil sterilization, aerial temperature, and fungicide exposure, all with and without growing plants.  Nitrous oxide efflux was altered  by the presence and size of a plant or carbon substrate addition to soil, increasing fertilizer levels, intermediate water status, and increasing temperature.  Significant interactions were observed among the controlling factors.