摘要：The objective of this research is to generate and cross-compare cost-effectiveness estimates of on-field (improved timing, rate, and application method) and off-field (restoring wetlands and establishing vegetative filter strips (VFSs)) approaches to reducing reactive nitrogen loadings. The analysis is based on economic and biophysical models that we’ve designed to evaluate public water quality conservation strategies. Results indicate that increasing the use of onfield nitrogen conservation practices, targeted to lands in corn-corn rotation (with a nitrogen-removal cost of $0.17 per pound), is the most cost-effective nitrogen conservation strategy. But the cost of further reductions in nitrogen losses by offering incentives to farmers with a corn-soybean rotation rises to $0.62 per pound. The authors found that wetland restoration is the second most cost-effective strategy. The average nitrogen removal cost of five- to ten-acre wetlands ranges from $0.23 to $0.24 per pound – when the wetlands are located to receive aquatic nitrogen flows. Nitrogen removal by VFS, in a best-case scenario, costs $0.41 per pound, but could be much higher. The analysis and results are based on conditions within a single Ohio county, two crop rotations, and a limited number of wetland options. However, the approach used here can be applied to assess different mixes of conservation practices and to determine which conservation practices are most cost-effective.
关键词：cost-effective conservation; agricultural nitrogen loadings; targeting nitrogen control; wetlands as nutrient filters; nitrogen BMP policies; cost-minimizing nitrogen control
