Crop management effects on the energy and carbon balances of maize stover-based ethanol production

Abstract

This study was conducted to identify the crop management options-the combinations of various cultivars, irrigation amounts, planting dates, and soils-that would maximize the energy sustainability and eco-friendliness of maize (Zea mays L.) stover-based ethanol production systems in the Mississippi Delta. Stover yields simulated with CERES-Maize were used to compute net energy value (NEV) and carbon credit balance (CCB), the indicators of sustainability and eco-friendliness of ethanol production, respectively, for various scenarios. As the results showed, deeper soils with higher water holding capacities had larger NEV and CCB values. Both NEV and CCB had sigmoid relationships with irrigation amount and planting date and could be maximized by planting the crop during the optimum planting window. Stover yield had positive effects on NEV and CCB, whereas travel distance had negative. The influence of stover yield was larger than that of travel distance, indicating that increasing feedstock yields should be emphasized over reducing travel distance. The NEV and CCB values indicated that stover-based ethanol production in the Mississippi Delta is sustainable and environmentally friendly. The study demonstrated that the energy sustainability and eco-friendliness of maize stover-based ethanol production could be increased with alternative crop management options.