This program is just one example of an integrated Research, Education and Extension project that has positively impacted water quality. Please check back periodically for other highlighted programs.

Paired Watershed Studies for Nutrient Reductions in the Minnesota River Basin

Situation Actions Impacts

SITUATION:

The Minnesota River is one of the most polluted waterways in Minnesota, with sediment and phosphorus being primary concerns. In Minnesota, most of the water quality improvement projects are organized by local government or by non-governmental organizations. To date, they have not been very successful at addressing nutrient reductions from cultivated cropland, including nutrients from land applied manure and fertilizers. Most water quality improvement efforts have focused on reducing pollution from point sources, septic systems, urban stormwater, and feedlot runoff. Farmer-initiated efforts to improve water quality are important in watersheds with significant non-point source pollution. However, producers have been reluctant to adopt new management practices without research documenting the environmental improvements gained, as well as the direct and indirect costs from potential yield reductions.

For real progress in reducing non-point source pollution, it is important that producers be directly involved in determining the best managment practices (BMPs) most feasible for adoption, the cost of adopted BMPs, and the effectiveness of BMPs in reducing non-point source pollution. Farmers want to take an active role in identifying practices that improve water quality. USDA personnel want to know which practices effectively improve water quality while maintaining agricultural productivity.

ACTIONS:

This project uses a coalition of producers, agency personnel, and researchers at the University of Minnesota to evaluate BMPs implemented at the watershed scale to improve water quality. The goals of the project are to:

The project uses two adjacent, 2800-acre agricultural watersheds in Nicollet County, Minnesota. These watersheds each have approximately three miles of county ditch, along which there are fifteen producers who farm corn and soybeans with a mix of hog and dairy operations. Automated water quality samplers were installed at the mouth of each watershed in the summer of 2001, and water samples have been collected for three years. Farmers operating within both the treatment and control watersheds have been surveyed for three years to identify farm management practices and production costs.

After a one-year baseline monitoring period, farmers in the treatment watershed were visited to discuss the types of changes in management they would be willing to make to improve water quality. BMPs were implemented in the treated watershed on about 49%, 63% and 56% of the land for the 2003, 2004 and 2005 crop years respectively. These BMPs included grid soil sampling for phosphorus, conversion from moldboard plowing to multi-tool plowing on corn ground, manure hauling, replacing surface tile inlets with hikenbottom risers, and installation of riparian buffer strips. Farmers were paid to install BMPs at rates typically found in state and federal programs. No changes in management were made in the control watershed.

IMPACTS:

Economic Impacts
Results from this project will be used to evlauate the economic costs and benefits of using various BMPs to improve water quality. The economic analysis will include effects of soil type and farm size, as well as impacts of targeting versus not targeting BMPs to specific portions of the watershed.

Environmental Impacts
One goal of the project is to improve water quality by accelerating the adoption of farmer-selected BMPs to reduce sediment and phosphorus losses. The results from this project will help determine what levels of BMP adoption are needed to improve water quality, including which BMPs are most effective, and how long it takes to see improvements in water quality.

Erosion modeling with RUSLE2 showed a 41% reduction in sediment delivered from fields that had been converted from moldboard plowing to combination tool plowing.

Phosphorus modeling with the Minnesota Phosphorus Index showed that 20% of the watershed area was in the high or very high risk categories for phosphorus loss to surface waters. Implementation of BMPs was estimated to reduce phosphorus risks from high or very high on this 20% area to very low, low or moderate risks.

Quality of Life Impacts
The project has directly involved about 30 farmers to improve their farm management practices and local water quality. The hope is that these changes will give farmers greater farm profitability, while reducing the transport of sediment and phosphorus to the Minnesota River.

It has been found that farmers are willing to make changes in their management practices to improve water quality. The level of adoption depends on their age, farm size, economic situation and production characteristics. The most suitable BMPs vary from farm to farm to accommodate the inherent differences in each operation. The BMPs that farmers are most likely to adopt include reduced tillage of corn residue, grid soil sampling for variable rate phosphorus application and elimination of surface tile inlets. Farmers are moderately receptive to BMPs such as installation of riparian filter strips and fall no-tillage of soybean residue, requiring increases in incentive payments beyond levels normally paid by government programs. Farmers are very resistant to BMPs involving changes in nitrogen fertilizer management.

 

For more information about the Minnesota River Basin Paired Watershed Studies, contact Dr. David Mulla of the University of Minnesota or visit the following websites: