Land resources are becoming progressively more constrained with increasing demands for food, feed, fiber, and now fuel production. Developing strategies to intensify crop production without increasing the negative impacts on water, soil, and air resources are critical. Much of the best agricultural lands are dominated by corn-soybean rotations with winter fallow periods. There has been interest in spatially diversifying and temporally intensifying production of the farm landscape to improve water quality and climate stabilization. Winter cover crops are one strategy to reduce nutrient losses over winter, but they have not been widely adopted. Harvested cover crops, or double crops, of winter small grains are common in some regions. Our objective was to quantify ecosystem services through increased diversity of crops in the farm landscape and evaluate strategies to reduce the hurdle rates for this increased diversity in corn-soybean growing regions in the US.
Reduction in nitrate leaching was the highest valued biophysical indicator for ecosystem services provided by the winter double crops, then soil carbon and N2O emissions. Although rye is a common cover crop to reduce the environmental impacts of crop production and can provide significant ecosystem services, it was never economically viable as a winter double crop. In contrast, we found that in addition to significant value from ecosystem services with planting winter small grains, they also had lower breakeven prices and yields leading to greater potential as a cellulosic bioenergy feedstock. We found that identifying a new market for straw, such as a feedstock for cellulosic ethanol, significantly improved the economic viability of barley and wheat further north into the Corn Belt.