Submitted to: Electronic Publication
Publication Type: Other
Publication Acceptance Date: 8/15/2004
Publication Date: 9/1/2004
Citation: Johnson, J.M. 2004. Corn residue is a valuable product. CSANews 49(9). Available: http://www.asa-cssa-sssa.org/news.html.
Technical Abstract: A renewable energy source can replace or reduce dependence on foreign energy supplies. The corn residue (stalks and leaves) after grain harvest can be used to make ethanol, a domestic and renewable biofuel. Scientists from the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) studied the risks and benefits of using corn residue to produce ethanol with funding from the United States Department of Energy (US-DOE). Ethanol is made from corn residue in a process similar to the making ethanol from corn grain. After fermenting the corn residue, a by-product remains that is lignin rich. Lignin is a complex compound found in plant cell walls, which is difficult for microbes to breakdown. Lignin is about 65% carbon. For this laboratory study conducted in 2001, the by-product was applied to two soils, which differed in soil organic matter. One soil had a high level of soil organic matter collected from a site with minimal soil erosion. The other soil had very low soil organic matter and was collected from a highly eroded site. Many soil properties were monitored on soils, which were treated with corn residue or by-product. Inferences were made on the ability of the by-product to improve/stabilize these soil properties. One of these parameters was humic acid, which is an indicator of soil organic C. Another parameter was aggregate stability, which is an indicator of how well a soil can resist erosion. Both of these parameters increased when the by-product was added to the soil at a rate equivalent to 5 ton/acre. While there are potential benefits from producing ethanol from corn residue, environmental risks, such as increased erosion due to removing corn residue, must be evaluated before corn residue removal becomes wide spread. Soil-specific removal rates should be determined for profitable residue use with minimal erosion, nutrient and soil organic matter losses. This information is important to the US-DOE in determining the feasibility of using corn residue for ethanol production. The use of corn residue as a fuel potentially provides an additional commodity for farmers and aids in reducing dependence on non-renewable energy sources.