Utilization of Annual Warm-Season Grasses as a Biofuel Source and Feedstock By-Product

Joshua A. White, Rocky Lemus

Department of Plant and Soil Sciences, Mississippi State University, Starkville, USA.

DOI: 10.4236/ajps.2014.521342                

Abstract

Annual warm-season grasses such as forage sorghum, sorghum × sudangrass hybrid and sundangrass are highly productive and valuable feed crops (rotational crop and silage). In addition, sugar in the stems of these warm-season grasses can be extracted and fermented, while the cellulose in the bagasse (pressed stalk) can be used for feedstock or cellulosic ethanol, making them versatile to both the forage and biofuel industry. Twelve annual warm-season grasses including forage sorghums, sudangrass, sorghum × sudangrass hybrid, and pearl millet were planted in 1.82 m × 3.35 m plots, harvested and treated as silage and hay before and after sap removal. Dry matter (DM) yield from a single harvest in 2011 and 2012 were collected and analyzed. Further analysis from the varieties includes evaluation for sap production, ^OBrix, crude protein (CP), Neutral Detergent Fiber (NDF), and Acid Detergent Fiber (ADF). Forage quality in silage was negatively affected by removing the sap before ensiling, producing quality similar to that of the hay samples. Sugar yields (SY) were not comparable to sweet sorghum yields reported in the literature, but when considering SY along with bagasse yield a few varieties may offer the potential as a dual purpose crop.

Keywords

Bioenergy, Sorghum, Dual Purpose Crop, Ethanol from Sorghum Sap

Conflicts of Interest

The authors declare no conflicts of interest.

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