Evaluation of Eastern Gamagrass as Dual-Purpose Complementary Bioenergy and Forage Feedstock to Switchgrass

Abstract:

With an increase in global world population, the consumption of resources will be greatly enhanced. A search of alternative energy bioenergy resources such as switchgrass and gamagrass becomes an important task. In this study, we evaluated gamagrass’s bioenergy potential in comparison to switchgrass under different agricultural practices over three years. Both gamagrass and switchgrass were treated with 9 treatments that including a control with no nitrogen (N) application, one N application, two N applications, no N application with crimson clover or hairy vetch as cover crop, one N application with crimson clover or hairy vetch, and two N applications with crimson clover or hairy vetch. These treatments where carried out in 3 x 6 m² plots with four replicates for each treatment. Biomass productivity, cellulose, lignin, ash, protein, and element contents were measured. Results showed that different agricultural practices significantly influenced most of the variables measured. Compared to switchgrass, gamagrass produced lower biomass, more cellulose carbon, ash and protein, and Ca and K contents. The treatment of two N application with crimson clover had the highest aboveground productivity, but showed no significant differences with two N applications with hairy vetch, two N applications, one N application with hairy vetch, and one N application. Furthermore, compared to one N application, two N applications significantly increased aboveground productivity. Incorporating a cover crop also increased aboveground productivity. Our results showed that gamagrass is an effective biomass feedstock that produces slightly low biomass than switchgrass and their productivity can be further increased by adding a cover crop into the system.