Excerpt
The Energy Independence and Security Act (EISA), investments in lignocellulosic biorefineries by both the Department of Energy (DOE) and commercial entities, as well as many other market, security, and policy drivers, have increased public interest in harvesting nongrain biomass (i.e., crop residues) from our lands. This interest is positive because it is creating investment and entrepreneurial opportunities in many rural communities. However, it has also raised concern among many conservationists because some proponents of lignocellulosic energy may not realize how many important ecosystem services crop residues provide to the land. Crop residues on the soil surface are the first line of defense against the erosive forces of wind and rain. Residues also provide the building blocks for soil organic matter (SOM). As SOM is increased, crop nutrients are cycled more efficiently, soil micro- and macroaggregates are created, soil structure is stabilized, and soil water retention is increased. All these soil functions contribute to increasing crop productivity, water quality and quantity, and air quality. Furthermore, because SOM is >50% carbon (C), building SOM partially mitigates rising levels of an important greenhouse gas carbon dioxide (CO2) by C sequestration.
Fortunately, the scientific information base needed to answer the difficult questions of “if,…
Footnotes
Jane M.F. Johnson is Research Soil Scientist at the USDA Agricultural Research Service North Central Soil Conservation Research Laboratory, Morris, Minnesota. Douglas L. Karlen is Supervisory Soil Scientist and Research Leader at the USDA Agricultural Research Service National Laboratory for Agriculture and the Environment, Ames, Iowa. Susan S. Andrews is Ecologist and Leader at the National Soil Quality Technology Development Team and Director of the National Plant Data Center, USDA Natural Resources Conservation Service, Greensboro, North Carolina.
- © 2010 by the Soil and Water Conservation Society