Submitted to: Forest Service General Technical Reports
Publication Type: Abstract Only
Publication Acceptance Date: August 21, 2008
Publication Date: August 21, 2008
Citation: Johnson, J.M. 2008. Bioenergy: Agricultural Crop Residues [abstract]. U.S. Forest Service. General Technical Report NRS-P-31. p. 21.
The increasing cost of fossil fuels especially natural gas and petroleum as well as a desire to curtail greenhouse gas emissions are driving the expansion of bioenergy. Plant biomass (woody, grain and nongrain) is a potential energy source. Prior to the Industrial Revolution, plant biomass was a major fuel source for heating and cooking. The energy paradigm is shifting to renewable sources of energy with agronomic and forest products expected to make a significant contribution. The United States is one of the largest producers and users of fuel ethanol with corn grain as the primary feedstock. Critics and proponents alike recognize that alone ethanol from corn grain can not replace gasoline. Considerable financial and research efforts have and are going into the development of commercially-viable cellulosic ethanol production. In addition, utilization of thermochemical platforms (e.g., gasification) is expanding. Regardless of the energy platform, biomass harvest must be conducted in a sustainable manner. The potential risk and benefits vary among the various feed-stocks. Non-grain biomass has other uses: animal feed and bedding, protecting the soil from erosive forces, and providing the raw material for maintaining and building soil organic matter. Excess harvest of crop biomass increases the risk of erosion, loss of soil organic matter and thereby, the risk of declining productivity. The amount of biomass inputs required to maintain soil organic carbon exceeds the amount required to limit wind and water erosion to "T" (soil tolerance levels). Soil and water conservation benefits must be included in any biomass assessment to prevent long-term environmental damage as the nation seeks near-term solutions to energy problems. Strategies to minimize potential negative impact of bioenergy while striving to maximize benefits will be discussed.