Five Year Biomass and Ethanol Yields of Corn, Sweet Sorghum, and High Biomass Sorghum Grown on Marginal Lands.

Emerging biofuel feedstock systems are poised to have a lasting effect on Midwestern USA marginal soils by converting from grasslands to cultivated systems. Three annual bioenergy crops, corn (Zea mays L.), sweet sorghum (Sorghum bicolor (L.) Moench), and high biomass sorghum were grown in rotation with soybean (Glycine max L.) for five years at two Missouri locations, following the conversion of the land from perennial grass to row crop systems. Intermittent drought occurred in both sites during three of the five years notably reducing yield; a terminal drought in 2011 reduced sorghum yields and inhibited maize grain development at both sites. Overall theoretical ethanol yields from sweet sorghum were greater than from maize. The central Missouri site maintained greater dry matter yield (DM), and theoretical ethanol yield than the southwestern Missouri site. Due to the occurrence of drought during the study, the findings have relevance for evaluating marginal land management impacts in a changing climate.