Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2007
Publication Date: 6/8/2007
Citation: Johnson, J.M., Sharratt, B.S., Reicosky, D.C., Lindstrom, M.J. 2007. Impact of high-lignin fermentation byproduct on soils with contrasting soil organic carbon content. Soil Science Society of America Journal. 71(4):1151-1159. Interpretive Summary: Corn stalks and other crop residues can be used for energy. The ability to make liquid fuel, like ethanol, from corn stalks has become a reality. This process is becoming commercially viable and will play an important role in providing energy in the United States. After making ethanol from the corn stalks, the left over stuff or by-product contains a high percentage of lignin, which does not break down easily. The by-product may be used to make other energy products. It also may have value by adding back to the soil and replacing some of the carbon removed in the corn stalks. It is critical to return enough carbon and other nutrients to soil to keep it healthy and productive. This study shows that the by-product improves soil properties, related to soil productivity. This study also studied how corn and soybean grow if sown in soil to which the by-product was added. Biomass industry and corn producers will benefit from deciding the best uses for the by-product.
Technical Abstract: Use of agricultural biomass as biofuel may partially offset energy requirements currently fulfilled by nonrenewable fossil fuels. Corn stover is rich in cellulose and hemicellulose, which can be converted to sugars and fermented to ethanol, resulting in a high lignin fermentation by-product (HLFB). The HLFB could be used to produce steam or electricity; or applied to soil to improve soil properties. We had two objectives: (1) to determine if sufficient HLFB could increase humic acid and other soil properties (e.g. aggregate stability (AS), water-holding capacity (WHC) and bulk density (Db)) in two soils with contrasting levels of soil organic carbon (SOC) content and (2) to assess the impact of HLFB on corn and soybean growth. We addressed the first objective by amending two soils with HLFB or ground corn stover incubated in collars. The flux of CO2 was monitored, and after incubating for 118 days, soil chemical and physical parameters were determined. The second objective was addressed using a microcosm approach growing plants in a mixture amended with 1.0 g m-2 corn stover, 1.0 g m-2 HLFB or not amended, either in a growth chamber, greenhouse and outside. The results of the soil column study indicated addition of HLFB increased CO2 emission, WHC, humic acid and AS and decreased Db. Corn and soybean growth was not affected by HLFB. In anticipation of the development of a cellulosic fermentation industry, the expected economic and environmental benefits of improving soil properties by returning this HLFB to the soil needs to be assessed.