Submitted to: American Society of Agronomy Special Publication
Publication Type: Book / Chapter
Publication Acceptance Date: 12/10/2008
Publication Date: 5/1/2011
Citation: Johnson, J.M., Archer, D.W., Karlen, D.L., Weyers, S.L., Wilhelm, W.W. 2011. Soil management implications of producing biofuel feedstock. In: Hatfield, J. and Sauer, T., editors. Soil Management: Building a Stable Base for Agriculture. Madison, WI: American Society of Agronomy Special Publication. American Society of Agronomy and Soil Science Society of America. p. 371-390.
Interpretive Summary: There is a strong interest in developing non-food biomass feedstocks for energy. These non-food feedstocks are domestic and renewable but must be produced in a way that does not harm the environment. Crop residue and grasses can be used as bioenergy. Crop residues include all the above-ground plant parts except the grain. They have multiple functions in the field as they, protect soil from erosion, provide energy for soil organism, and are converted into soil organic matter. Perennial grasses can also be grown and harvested for biomass feedstocks, but doing so will require changes in current farming practices. The amount of fertilizer that needs to be applied may increase to replace the nutrients removed in the residue or grass. New or modified equipment will be needed to harvest these products. This chapter examines when and how much of the non-grain biomass can be harvested to use for bioenergy. It also stresses the importance of using farming practices that protect soil, water and air resources when crop residues and grasses are harvested. This chapter provides a concise summary of management issues with plant-based energy. This information will benefit producers, agricultural consultants, scientists, industry leaders, policy makers and the general public by educating them about management issues associated with plant-based energy.
Technical Abstract: The demand for domestic, renewable energy resources and the need for more stable and higher commodity prices for farmers and rural communities are drivers for the developing bioenergy industry. First generation feedstocks focused on corn (Zea mays L) and soybean (Glycine max. L. [Merr.]) grain in the U.S. Corn-Soybean Belt, but a grain-based energy industry raises concerns regarding the balance among food, feed, and fuel use of food crops. Non-grain plant biomass can be used as bioenergy feedstocks. While incorporating perennial species into current cropping systems may address some concerns, this has agronomic and environmental management implications. Historically, harvesting crop residue was limited to on-farm use related to animal husbandry. Routine broad-scale biomass harvest needs to be managed such that it does not exacerbate soil erosion or loss of soil organic matter. Furthermore, biomass harvest must account for additional nutrient removal and may modify plant water use. Biomass harvest will vary among crops or even within a single crop (e.g., stover or cobs). Harvesting biomass must be economically viable, with biomass feedstocks priced at least high enough to cover costs of production (e.g., additional fertilizer, additional machinery, transportation and storage). Agronomic crop residues are expected to be among the first biomass feedstocks harvested, but specific material will vary by region and season. It is paramount that a bioeconomy be based on sound agronomic, environmental and social principles. Protecting soil, water and air resources is essential for sustainable development and must be considered as the entire bioenergy industry develops. [REAP publication]