Sweet Sorghum [Sorghum bicolor (L.) Moench] Biomass Production for Biofuel and the Effects of Soil Types and Nitrogen Fertilization

Abstract

This research aimed to determine the optimum nitrogen fertilization rate on three soils for producing biomass sweet sorghum (Sorghum bicolor cultivar M81E) and corn (Zea mays cultivar P33N58) grain yield and to compare their responses. The research was conducted in Missouri in rotations with soybean, cotton, and corn. Seven rates of nitrogen (N) were applied. Sweet sorghum dry biomass varied between 11 and 27.5 Mg ha−1) depending on year, soil type, and N rate. Nitrogen fertilization on the silt and sandy loam soils had no effect (P > 0.05) on sweet sorghum yield grown after cotton and soybean. However, yield increased in the clay soil. Corn grain yielded from 1.3 to 12.9 Mg ha−1, and 179 to 224 kg N ha−1 was required for maximum yield. Increasing biomass yield required N application on clay but not on silt loam and sandy loam in rotations with soybean or cotton.