Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Great Lakes Region

On October 12, 2011, NRCS Chief Dave White announced the release of the CEAP-Cropland report on the effects of conservation practices on cropland in the Great Lakes Region. This report is the third in a series of regional reports that continues the tradition within USDA of assessing the status, condition, and trends of natural resources to determine how to improve conservation programs to best meet the Nation's needs. These reports use a sampling and modeling approach to quantify the environmental benefits that farmers and conservation programs are currently providing to society, and explore prospects for attaining additional benefits with further conservation treatment.

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Computer modeling simulations indicate that conservation practice use in the Great Lakes region has reduced sediment, nutrient, and pesticide losses from farm fields. However, there remain significant opportunities for reducing nonpoint agricultural sources of pollution.

Major findings from the study are listed below. More specific details on effects of practices are in the full report and the summary documents.

The voluntary, incentives-based conservation approach is achieving results. Structural practices for controlling soil erosion are in place on 26 percent of all cropped acres in the region and on 37 percent of the highly erodible cropland. Eighty-two percent of the cropland acres meet criteria for no-till (32 percent) or mulch till (50 percent), and all but 9 percent have evidence of some kind of reduced tillage on at least one crop in the rotation. Adoption of conservation practices has reduced wind erosion by 44 percent and edge-of-field waterborne losses of sediment by 47 percent, losses of nitrogen with surface runoff by 43 percent, losses of nitrogen in subsurface flows by 30 percent, and losses of phosphorus (sediment attached and soluble) by 39 percent.

Opportunities exist to further reduce sediment and nutrient losses from cropland. The study found that 19 percent of cropped acres (2.8 million acres) have a high level of need and that 34 percent (5 million acres) have a moderate level of need for additional conservation treatment. The remaining 47 percent of the cropped acres have a low level of need for additional treatment.

Comprehensive conservation planning and implementation are essential. The resource concern with the most widespread need for additional conservation treatment related to cropland in the region is nitrogen loss in subsurface flows. The need for additional conservation practices to address excessive phosphorus loss (sediment adsorbed and soluble) from fields is also important but less so than for nitrogen.

Targeting enhances effectiveness and efficiency. Use of additional conservation practices on acres that have a high need for additional treatment梐cres most prone to runoff or leaching and with low levels of conservation practice use梒an reduce sediment and nutrient per-acre losses by about twice as much on average as treatment of acres with a moderate level of conservation treatment need.

Technical information on the methodology for CEAP Cropland studies, including the one on the Great Lakes Region, and documentation reports on the modeling methodology, models and databases are available as part of the Cropland National Assessment. Detailed information on the CEAP Cropland Farmer Surveys conducted by NASS is available.

(Source: USDA, http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/)