With increasing concerns on energy, food, and environmental security, viable domestic substitutes to foreign oil other than bioethanol are needed. Production of biofuel and biobased-products from lignocellulosic-rich biomass of energy crops presents several advantages: it uses non-food biological feedstocks that prevents competition with food and feed supplies, and it is a renewable energy source and under a well-managed system can provide numberous benefits to soil and environment. Adopting winter cover crops in energy cane-sweet sorghum rotation system collectively employs logical approaches to ensure high-yielding, sustainable, and environment-beneficial feedstock production system in the South Central U.S. region. The goal of this project is to evaluate and document the production potential, effectiveness, and economic feasibility of energy cane-sweet sorghum rotation with winter cover crop system in Louisiana. The specific objectives include: 1) determine and document the potential increase in feedstock production from sweet sorghum and energy cane residue, 2) compare and document the effectiveness between winter cover crops and cane residue as soil surface cover on energy cane productivity, nutrient cycling, and soil quality, 3) evaluate the economic feasibility of different cover crop strategies in energy cane production. Field experiment will be established at two different soil types with the following treatments: (T1) energy cane with fallow period and without cover crops, (T2) energy cane-sweet sorghum without winter cover crops, (T3) energy cane-sweet sorghum with winter cover crops planted right after harvesting and plough out of the 2nd ratoon cane, and (T4) similar to T3 + winter cover crops after planting and harvesting of plant cane and 1st ratoon cane. Soil nutrient content, soil quality parameters, composition of runoff water samples, nutrient removal by main crops and cover crops, biomass yield, and fiber content will be determined. All these data will be used to verify if the implementation of enery cane-sweet sorghum rotation with winter cover crops will result in significant increase in feedstock production for biofuels and biobased products and improved soil nutrient content and quality. In addition, the outcomes of this project will be used to determine if the logistics of establishing cover crop system are economically feasible. We expect that the outputs of this project will be instrumental to understand the agronomic and economic contribution of utilizing two energy crops in a cropping system and energy cane residue to feedstock production. More importantly, we expect to deliver an established, well-synchronize cover/double cropping system that can be adopted in the South Central U.S. region where energy cane and sweet sorghum are the main energy crops to maximize production of lignocellulose-rich biomass.
