Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2004
Publication Date: 7/28/2004
Citation: Johnson, J.M., Wilhelm, W.W., Hatfield, J.L., Voorhees, W.B. 2004. T-values, corn stover removal and sustained productivity [abstract]. Soil and Water Conservation Society Meeting Abstracts. Available: http://www.swcs.org/t_what2004confabstracts.htm. Interpretive Summary:
Technical Abstract: The US Department of Energy and private enterprise are developing the technology necessary to use high cellulose feedstock, such as crop residues, for ethanol production. Based on current production levels, corn (Zea Mays L.) stover has potential as a biofuel feedstock. Crop residual biomass (stover or straw) is a renewable and domestic fuel source, which can reduce the rate of fossil fuel use (both imported and domestic) and provide an additional farm commodity. Crop biomass protects the soil from wind and water erosion, provides inputs to form soil organic matter (a critical component determining soil quality), and plays a role in nutrient cycling. Crop residual biomass impacts radiation balance and energy fluxes, and reduces evaporation. Therefore, the benefits of using crop biomass as fuel, which removes biomass from the field, must be balanced against negative environmental impacts (e.g. soil erosion), maintaining soil organic matter levels and preserving or enhancing productivity. Our objective is to summarize published works for the impacts of wide-scale corn stover collection on sustained production capacity and related soil processes in the Corn Belt soils. Most estimates for predicting the availability of crop biomass are based on T values. Soil and crop responses to biomass removal ranged from negative to negligible. The range of crop and soil responses to crop biomass removal was attributed to interactions with climate, management and soil type. Harvest rates must vary based on regional yield, climatic conditions and cultural practices. The challenge is to define harvest rates that ensure sustained productivity.