Sweet Sorghum as Biofuel Feedstock: Nutrient Source, Yield, Soil Quality, Economics, and Manure Transportation

摘要

A reticular set of environmental, agricultural, and energy issues may be alleviated through beneficial use of poultry litter as a nutrient source to poor quality soils for production of sweet sorghum [Sorghum bicolor (L.)Moench] as biofuel feedstock. This study assessed the viability of producing a biofuel crop using an organic by-product as an alternative to commercial fertilizer (CF). Sweet sorghum was established annually for 3 yr on a relatively poor drainage, low organic matter, and low pH soil of eastern Oklahoma. Poultry litter was annually applied at four different application rates and CF applied at equivalent N, P. and K. Sorghum biomass yield and changes in soil properties were monitored. Yield and input costs were used to determine economic return and optimum distances for litter transportation. After 3 yr of litter application, several soil quality parameters increased for litter-amended soils compared to CF. Although economic return was greater for litter, yields from litter were not significantly different from CF. Overall biomass yields and economic returns increased with higher nutrient rates and varied each year because of variable weather. As a result of increased economic return from litter compared to CF, litter could be transported to various distances depending on application rate and ethanol price. Use oflitter as a nutrient source for growing sweet sorghum as biofuel feedstock can be economically sustainable and potentially improve water quality in environmentally sensitive watersheds, improve soil quality of marginal land, and reduce dependence on fossil fuels.