|JOLLEY, LEONARD - Natural Resources Conservation Service (NRCS, USDA)|
|SPEATH, KEN - Natural Resources Conservation Service (NRCS, USDA)|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2010
Publication Date: 2/6/2011
Citation: Weltz, M.A., Jolley, L., Speath, K. 2011. National estimates of soil loss on rangelands [abstract]. Society for Range Management. p. 72.
Technical Abstract: Since 1995, an interagency group composed of the Natural Resources Conservation Service, Agricultural Research Service, and U.S. Geological Survey have worked together to develop a robust field approach for National Resource Inventory (NRI) on rangeland. The new NRI protocols are designed to detect long-term, years to decades, changes in the condition on rangeland ecosystems, and monitor short-term impacts which may be of immediate concern. A new process-based model was developed by Agricultural Research Service for assessing soil erosion rates on rangelands. The Rangeland Hydrology and Erosion Model was used to calculate runoff and erosion at the hillslope scale for over 10,000 NRI points in the 17 western states on non-federal rangelands. Nationally, 20% of non-federal rangelands generate over 65% of the average annual soil loss. Over 72 million ac (18%) would likely benefit if it was treated to reduce soil loss to below 1 ton ac-1 year-1. Between 23 and 29% (92 to 106 million ac) of the nation's non-federal rangelands are vulnerable to accelerated soil loss (soil erosion > 1 ton ac-1 year-1) if assessed as a function of vulnerability by using the risk of a runoff event of a given magnitude (25 or 50 year return event). Adoption of the concept of risk and vulnerability will allow land managers to be proactive in preventing accelerated soil loss rather than concentrating on repairing degraded lands which is a far more costly approach.