Location: Crop Protection and Management Research
Title: The integration of sorghum as a biofuel species into cropping system of the Southeastern U.S. Authors
Submitted to: Tappi Pulping Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 8, 2012
Publication Date: October 17, 2012
Citation: Scully, B.T., Webster, T.M., Olson, D.M., Strickland, T.C., Knoll, J.E., Anderson, W.F. 2012. The integration of sorghum as a biofuel species into cropping system of the Southeastern U.S. Tappi Pulping Conference Proceedings. 1642. Technical Abstract: Abstract The climate in the southeastern U.S. provides a robust environment for the integration of annual biofuel species into the region’s cropping systems. Mild winters, a 7-8 month summer crop growing season, reasonably adequate rainfall and a diverse array of adapted crop species provide an ideal opportunity to introduce an annual biofuel crop into the existing agricultural system. The biofuel sorghum cultivar ‘Blade 5200’ was examined in crop rotation schemes that included winter cover crops in rotation with cotton and sorghum in low input system. Experiments were repeated on adjacent farms so that cotton and sorghum occurred at one location each growing season. In this experiment, winter cover crops, which included rye as the regional standard of rye, and several nitrogen-fixing legumes, were grown from October through April and used to improve soil quality and productivity. Cotton and sorghum were grown sequentially behind the winter legumes from May through September. Nine treatments including narrow-leaf lupin, winter pea, white vetch, faba bean, and crimson clover, along with rye, two fertilized and a non-fertilized control were grown in a strip split plot design with four replications, where legumes and controls were designated as main plots. These main plot treatments were further divided into subplots based on how the cover crop was handled prior to the summer crop planting. Subplots included: 1) rolling of the cover crop to form a horizontal mulch; 2) clipping the cover crop at the soil surface and biomass removed from the plots; and 3) leaving the cover crop untouched in the field to serve as a refugia for beneficial insects. Results indicated that Blade 5200 sorghum grown after the narrow-leaf lupin, winter pea or white vetch produced the highest biomass yield, surpassing other winter crops and controls. Biomass production of sorghum following faba bean and clover was no different than the standard non-planted winter fallow (fertilized and non-fertilized) controls or rye. For most treatments, the rolled subplots allowed the sorghum to achieve higher yield levels than the subplots in which the biomass was removed. After three cropping cycles, these results indicated biofuel sorghum cultivars exhibit the potential to produce desirable levels of biomass when grown in combination with certain winter legume cover crops in a low input system.