HR: 08:00h
AN: B51B-01 INVITED     [PDF]
TI: The Effects of Residue Management on Soil Carbon Sequestration in the U.S. Cropland
AU: * Lal, R
EM: lal.1@osu.edu
AF: Rattan Lal, The Ohio State University 2021 Coffey Road, Columbus, OH 43210 United States
AU: Follett, R
EM: rfollett@lamar.colostate.edu
AF: Ron Follett, USDA-ARS P.O. Box 301 S. Howes St., Ft. Collins, CO 80522 United States
AU: Kimble, J M
EM: johnkimble@usda.gov
AF: John Kimble, USDA-NRCS 100 Centennial Mall North, Lincoln, NE 68508 United States
AB: The cropland area in the U.S. is 157 Mha or 17.1% of the total land area of 916 Mha. Of this, 119 Mha is rainfed, 22 Mha irrigated and 16 Mha idle cropland. Some steeplands and other marginal soils are prone to accelerated erosion and other soil degradative processes. Total cropland are subject to accelerated erosion is 44 Mha, and secondary salinization occurs on 0.2 Mha of irrigated cropland. Conversion of plow till to conservation tillage, residue management, incorporation of cover crops in the rotation cycle, integrated nutrient management, and restoration of degraded soils are among the recommended management practices to sequester C and improve soil quality. The potential of soil C sequestration in the U.S. cropland is 45 to 98 Tg C/y for adoption of recommended management practices, 9 to 13 Tg C/y for CRP, and 13 to 31 Tg C/y for restoration of eroded cropland. This potential is contingent upon return of crop residue mulch and other biosolids so that C input into the soilscape exceeds the C losses by mineralization, erosion and leaching. However, with growing interest in alternate uses of crop residues (e.g., biofuel), it is important to assess the soil-specific needs for soil C sequestration and to estimate the amount which can be spared for other uses. Possible adverse impact of residue removal on soil C sequestration may be minimized by growing a winter cover crop which can compensate the loss of residue and also, in the case of legumes, enhance soil fertility. This presentation explores alternate uses of residue for soil C sequestration and biofuel production.
DE: 1600 GLOBAL CHANGE (New category)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting