Conservation considerations for sustainable bioenergy feedstock production: If, what, where, and how much?

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,…