The environmental implications of large-scale bioenergy cropping systems are not well understood, making the provision of available conservation implementation resources difficult and inefficient. In order for biofuels to be a sustainable solution to fossil fuels, their cultivation must avoid intensifying negative environmental impacts. To address these issues, the following research objectives were developed: 1) determine if pesticides are suitable for lignocellulosic ethanol feedstocks 2) provide critical information to determine the suitability of bioenergy crops on a variety of types of agricultural land in Michigan 3) determine the possible environmental impacts of bioenergy cropping systems on sediment, nitrogen, and phosphorus yield to surface waters 4) determine the implications of bioenergy-associated pesticides on aquatic ecosystems and human consumption 5) obtain information to aid in watershed-scale decision making regarding landuse management. The Soil and Water Assessment Tool (SWAT) was used to understand the impacts of large-scale bioenergy crop expansions on pollutant loads and concentrations. Results indicate that intensive bioenergy crops such as corn and sorghum tend to increase sediment, nitrogen, and phosphorus loads to surface waters, whereas perennial grass species such as switchgrass, miscanthus, and native grass generally mitigate pollutants. Although herbicide treatments mainly positively influenced biomass accumulation in corn during field studies at the Michigan State University Agronomy Farm, the application of herbicides at a large-scale was found to increase the impairments of streams in Michigan on the basis of fish ecotoxicity and to a larger extent, human consumption thresholds. In general, this study reinforces the importance of maintaining a sustainable bioenergy cropping system implementation strategy to avoid environmental and human health risks.
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