Study Measures Greenhouse-Gas Emissions from Grazed Grasslands

A study by USDA scientists, published in Agrosystems, Geosciences & Environment Journal, evaluated the greenhouse-gas emissions from grazed grasslands in Oklahoma. Three of the pastures studied were native prairies and one was a planted single species of grass. The team found that in this hot, subhumid area, all the sites were net emitters of carbon dioxide on a yearly basis. All sites emitted small amounts of nitrous oxide, but the non-native site, which received fertilizer, emitted the most nitrous oxide. Scientist noted that, with nitrous oxide being three hundred times stronger at trapping heat than carbon dioxide, this difference really adds up. Meanwhile, soil organisms absorbed methane from the atmosphere at all sites, with the native sites absorbing more methane than the non-native site. Researchers are interested in determining just how much of the methane emissions from grazing animals grasslands can absorb.