TITLE OF PROJECT OR PROGRAM:
Renewable Energy Assessment Program (REAP)
USDA Agricultural Research Service
Domestic ethanol production is a strategy for reducing dependence on imported energy and release of greenhouse gases from use of fossil-energy-derived motor vehicle fuel. Federal and state governments are encouraging the use of ethanol. Initially energy crops, such as switchgrass, willow, and poplar, were targeted as sources of bio-energy, recently crop residues, especially corn stover and wheat straw, have been identified as a source of cellulosic biomass. However, the amount of crop residue needed to protect soil from erosion and to sustain soil organic carbon (SOC) stores constrains residue removal for bio-energy. Research over the past century has shown conclusively that crop production practices result in loss of SOC. Typically loss of SOC has detrimental effects on soil productivity and quality. Our objectives are to determine the amount of residue needed to protect the soil resource, compare economic implication based on the value of stover as bio-energy and C source, and provide initial harvest rate recommendations and guidelines. Products from this work will be 1) guidelines for management practices supporting sustainable harvest of residue, 2) algorithm(s) estimating the amount of crop residue that can be sustainably harvested, and 3) decision support tools and guidelines describing the economic trade-off between residue harvest and retention to sequester soil C. Delivery of this knowledge and these products to farmers and the biomass ethanol industry will promote harvest of stover and crop residues in a manner that preserves the capacity our soil to produce food, feed, fiber, and fuel.
DESCRIBE ANY NOTABLE RESULTS, OUTCOMES OR IMPACTS TO DATE, IF ANY:
PERFORMERS/OTHER PARTNERS (FEDERAL, STATES, OR LOCAL):
ARS laboratories in Lincoln, NE; Mandan, ND; Auburn, AL; St. Paul, MN; Ames, IA; Ft. Collins, CO; Pendleton, OR; Morris MN; W. Lafayette, IN.
Start Date: Jun 01, 2006 End Date: May 31, 2011