This chapter considers the emissions of ammonia (NH3), nitrous oxide (N2O), other oxides of nitrogen (NOx), carbon dioxide (CO2), methane (CH4), and non-methane volatile organic compounds (NMVOCs) from agricultural soils to which nitrogen (N)-containing fertilizers are applied. For NH3, emissions following application of animal manures to land are considered in SNAP code 100900, Manure Manageme...

Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respirati...

Cattle 's grazing of the locoweed Wahweap milkvetch (Astragalus lentiginosus var. wabweapensis) was evaluated on desert and foothill winter range during the winter of 1986 to 1987. Dry, dead stalks of Wahweap milkvetch that had grown in 1985 and 1986 made up 15% of cattle diets overall, and 24% of diets when cattle grazed gravelly benches where it was abundant. Nutrit ional quality of Wahweap m...

The contemporary southwestern United States is characterized by fire-adapted ecosystems; large numbers of federally listed threatened and endangered species; a patchwork of federal, state, and private landownership; and a long history of livestock grazing as the predominant land use. I compared eight sites in southern Arizona and New Mexico to assess the interacting effects of these characteris...