Biomass Production and Water: A Brief Review of Recent Research

The Energy Independence and Security Act (EISA) mandated an increase in the production of liquid fuels from renewable sources, including corn, soybeans, and perennial crops. Expanded corn production poses a risk to water quality, and expanded production of perennial crops for cellulosic ethanol may have positive effects on water quality as well as positive or negative impacts on water quantity. Nitrate contamination from corn production is greatest in regions with subsurface drainage systems. Sediment and phosphorus contamination are more likely to come from sloping soils. The risks to water quality can be reduced by conservation practices, such as planting winter cover crops, but the costs of implementing these practices represent a barrier to adoption when there is little or no benefit to the farm owner or operator. The magnitude of these impacts appears to be highly variable and there is a need for more empirical work to improve simulation models to quantify the impacts in different physiographic settings and at a range of scales.