Soil Health Impacts of Dedicated Biomass Energy Cropping Systems In the Southern USA.

Many annual and perennial grasses are being evaluated for their potential as dedicated bioenergy crops. We established a dedicated bioenergy cropping systems study at Arkansas State University to investigate the sustainability of various bioenergy crops and various sources of nitrogen with regards to soil and water quality and sustainability. Our objective for this part of the study was to determine the effecct of crop species and nitrogen source on soil health paramters. Aggregate stability was significantly affected by crop species, but not by nitrogen source. Active carbon was significantly greater in those treatments receiving N fertilizer of any type, while the specific crop species was not significant. After the second year of production, switchgrass (8 tons/acre) was producing twice as much biomass as eastern gamagrass (1.6 ton/acre) with high biomass sorghum (9 ton/acre) producing more than switchgrass. Research outcomes from this project will provide new knowledge in support of the sustainability of various dedicated energy crops and their management.  Proven sustainable options for growing dedicated energy crops in the southern region will allow growers to use best management practices in managing their farms.