Soil carbon dynamics and potential carbon sequestration by rangelands.
The USA has about 336 Mha of grazing lands of which rangelands account for 48%. Changes in rangeland soil C can occur in response to a wide range of management and environmental factors. Grazing, fire, and fertilization have been shown to affect soil C storage in rangelands, as has converting marginal croplands into grasslands. Carbon losses due to soil erosion can influence soil C storage on rangelands both by reducing soil productivity in source areas and potentially increasing it in depositional areas, and by redistributing the C to areas where soil organic matter mineralization rates are different. Proper grazing management has been estimated to increase soil C storage on US rangelands from 0.1 to 0.3 Mg C ha(-1)year(-1) and new grasslands have been shown to store as much as 0.6 Mg C ha(-1)year(-1). Grazing lands are estimated to contain 10-30% of the world's soil organic carbon. Given the size of the C pool in grazing lands we need to better understand the current and potential effects of management on soil C storage.
Schuma
G E
GE
USDA, ARS, High Plains Grasslands Research Station, Cheyenne, WY 82009, USA. gschuman@lamar.colostate.edu
Janzen
H H
HH
Herrick
J E
JE
D000383:Agriculture; D000821:Animal Feed; D000818:Animals; D000829:Animals, Domestic; D002244:Carbon / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D004784:Environmental Monitoring; D005390:Fires; D009930:Organic Chemicals; D006109:Poaceae / Q000502:physiology*; D012987:Soil
D009930:Organic Chemicals; D012987:Soil; D002244:Carbon