Evaluation of Bioethanol Production from Sweet Sorghum Variety Roger under Different Tillage and Fertilizer Treatments

Abstract

Sweet sorghum Sorghum bicolor (L.) Moench) is a promising crop for bioethanol production characterized by its high biomass yield, sugar-rich stalks, facile juice extraction, and ability to adapt to different production systems. The objective of this study was to assess the effects of cultivation practices (soil treatments) on the juice, sugar, and ethanol yields of sweet sorghum variety Roger. Three methods of tillage (minimum, traditional, and traditional tillage with rupture of the plow layer) and three types of fertilizers (inorganic, organic, and without fertilizer) were assayed. The best results of stem yield (44.3 tons/ha), juice production (25.6 m3/ha), concentration of soluble solids in the juice (16.9 °Brix), and juice ethanol yield (2.1 m3/ha) were obtained under a mixture of traditional plowing with plow layer breaking, applying an organic fertilizer. In addition, the extracted juice allowed yeast (industrial Saccharomyces cerevisiae PE-2) growth and conversion to ethanol without the need for nutrients supplementation. Therefore, sweet sorghum continues to be an interesting bioenergetic crop for production of first-generation biofuels.