Driftless Area Issues

Fragmentation of the Driftless Area among four states has exacerbated efforts to reverse negative land use trends that have serious consequences for water quality of the Mississippi River and its tributaries.  Since European settlement, changing land use has vastly increased soil exposure, disturbed habitat for wildlife throughout the region, and altered the hydrology of streams and rivers.  Land that was converted in the 1800’s from prairie or timber, to hay and pasture for dairy and meat production, is rapidly being replaced with annually tilled crops such as corn and soybeans.  Less than 1% of original native grasslands remain, and forest health has declined after a century of exploitative management. These trends have resulted in significant increases in soil erosion, sedimentation, and run-off.  Sediment delivery and poor water quality in some streams and rivers have resulted in the loss of habitat for many fish and other aquatic species.  Although the Upper Mississippi River and the US Fish and Wildlife Refuge spanning the length of this incredible resource provide habitat for a vast array of wildlife species, water quality issues stemming from agricultural inputs and human development have resulted in many serious impairments both in the river and beyond.  An estimated ninety percent of the nitrogen lost from this area is delivered to the Northern Gulf of Mexico where it contributes to the problem of hypoxia (low dissolved oxygen and related impairments of aquatic life).

Land Resources & Trends

The Driftless Area comprises nearly one-sixth of the area of the Upper Mississippi River Basin. The majority of the area is identified as Major Land Resource Area 105. (MLRAs were developed by the USDA’s Soil Conservation Service --today’s Natural Resources Conservation Service -- for inter-state, regional and national planning.) The remaining acres are the upper portions of the watersheds that flow into MLRA 105; most of which are in MLRA 104.

• MLRA 105, called the Northern Mississippi Valley Loess Hills, includes 22,210 square miles in Wisconsin, Iowa, Minnesota and Illinois. While the majority of land use in MLRA 105 is agriculture, small and moderate dairy and beef enterprises have been most prevalent, as is hay and pasture. Topographic relief and the potential for soil erosion are severe in MLRA 105. Karst topography makes the agricultural landscape extremely susceptible to nitrogen losses to groundwater and surface water. Groundwater-fed streams are capable of supporting native brook trout, but are sensitive to degradation from land use changes.

• MLRA 104, called the Eastern Iowa and Minnesota Till Prairies, comprises 9,700 square miles of flat to moderately sloping land, most of which is used for row-crop agriculture and intensive livestock production, especially hog production. Extensive artificial drainage of intensively farmed row cropland provides efficient delivery of nitrogen to surface water. MLRA 104 forms the headwaters for many watersheds in the western part of the region.

Land-Use Trends: The farm program provides powerful incentives to raise “program” row crops. This, combined with major structural changes in the livestock sector, has led to a shift in land use from hay and pasture to row crops, especially soybeans, throughout the region, including slopes with high soil erosion potential. Between 1982 and 1997, according to USDA National Resource Inventory surveys, the area has experienced several land use shifts:

• A 20% reduction in acreage of hay and pasture. Hay and pasture favor reduced runoff, minimal leaching of nitrate-nitrogen and very little soil erosion.
• A 60% increase in acreage of soybeans. On steeper slopes, this rotation poses a threat of severe soil erosion and leads to greatly increased leaching of nitrate nitrogen.
• Enrollment of 820,000 acres of cropland in the Conservation Reserve Program (CRP) by 1997. This helped to offset the effects of increased soybean production. Much of the CRP acreage came out of corn production, which declined by 13% over the period. However, since 1997 the contracts on much of the CRP land have expired, and many acres have been returned to crop production.

Fueling the Trends:
Among the forces behind these land use trends are four that stand out as especially significant:

• Continuing Dairy Herd Decline: Milk cow numbers declined by an average of 31% between 1982 and 1997 in Iowa, Minnesota and Wisconsin. This trend is continuing. According to projections by the Food Policy Research Institute at the University of Missouri, dairy cattle will decline by 32% in Minnesota, 22% in Wisconsin, and 11% in Iowa from 2000-2010. Local demand for hay and pasture has declined during that same time period resulting in hay and pasture conversion to annual crops on steep highly erodible lands.

• Beef cow reductions: In the period between 1982 and 1997, beef cow numbers in the three-state area declined by 33% in Iowa, 13% in Minnesota, and 6% in Wisconsin, further reducing the demand for hay and pasture.

• Federal Farm Program Incentives: The federal farm program provides additional incentives to shift production from hay and pasture to corn and soybeans. In recent years of depressed market prices, up to 70% of net farm income from corn and soybean production has come from federal payments based on acreage and yields of these program crops. Because hay and pasture are not eligible for federal payments, the economic return to these land uses has fallen sharply relative to corn and soybeans. Inadvertently, the federal farm program is fueling the trend from hay and pasture to row crop farming by selectively supporting only the latter.

• Habitat Degradation: As grasslands, woodlands and wetlands have been gradually converted for suburban developments or row crop production over the past several decades, and as fields have been tiled or ditched and watercourses have been straightened, the destructive forces of floods, stream bank erosion, sedimentation and nutrient contamination have been unleashed on downstream communities and on fragile fish and wildlife habitats. Habitat restoration can help reverse this trend.