Hotspots of Nitrous Oxide Emission in Fertilized and Unfertilized Perennial Grasses

作者：Cedric Mason, Cathelijne R. Stoof, Brian K. Richards, Srabani Das, Christine L. Goodale, Tammo S. Steenhuis · 发表于：Soil Science Society of America Journal · 年份：2017 · DOI：10.2136/sssaj2016.08.0249 · 被引用次数：19 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Peatlands and Wetlands Ecology

Core Ideas We studied hotspots of nitrous oxide emission from perennial grasses on wet soil. Hotspots occurred in a limited range of soil moisture and temperature conditions. Hotspots recurred more frequently at specific places over a three year period. Hotspots of nitrous oxide (N 2 O) emission are thought to contribute substantially to annual emissions from agricultural soils. We observed N 2 O fluxes from fertilized and unfertilized C 3 and C 4 perennial grasses on a wet silt loam soil in New York, United States during the growing season in 2013, 2014, and 2015 using static chambers. Analysis of N 2 O hotspots within the research plots revealed that hotspots contributed between 34.3 and 39.1% of the total emissions, and constituted between 0.8% and 5.0% of all flux observations. Hotspots were more frequent and of greater magnitude in the fertilized treatments, and occurred when soil temperature was greater than 9.1°C and soil moisture was between about 40% and 80% water filled pore space (WFPS). A single chamber location in the fertilized switchgrass treatment was consistently a hotspot for N 2 O emission, suggesting that hotspots maintain a stable spatial pattern over extended periods. The maximum magnitude of N 2 O hotspot emission exhibited a relationship to soil temperature that is similar to that of the microbial growth rate constant.