Development of integrated bioenergy production systems using precision conservation and multicriteria decision analysis techniques

Abstract

Development of a productive advanced biofuels economy will require a suite of lignocellulosic feedstocks, including both agricultural residues and dedicated energy crops. This research utilizes precision conservation and multicriteria decision analysis (MCDA) techniques to model the integration of switchgrass (Panicum virgatum L.), a perennial bioenergy crop, into a corn (Zea mays L.)-producing field in Iowa, United States. The impacts of energy crop integration are quantified in terms of productivity, economics, and environmental performance. Management areas identified using a multi-objective optimization method are modeled using the Landscape Environmental Assessment Framework (LEAF) to calculate biomass availability and impacts to soil health, while the Water Quality Index for Agricultural Lands (WQIag) is used to assess the risk to surface water quality. The results show that subfield management zones optimized to reduce economic losses and maximize environmental performance are capable of improving the field's annual rate of soil organic carbon (SOC) gain by 69%, reducing annual soil erosion by 63%, and increasing sustainable biomass availability by 35%. Environmental improvements are valued at US$158 ha⁻¹ (US$64 ac⁻¹), making the integrated management system an effective financial loss mitigation strategy compared to conventional corn production when feedstock prices are greater than US$107 Mg⁻¹ (US$97 tn⁻¹). The results of this work demonstrate that the production of bioenergy crops integrated with commodity row crops can be a tenable means to improve the overall production of a field, improve the profitability of row crop farming, and preserve or improve water and soil resources.