Study pinpoints conversion of fragile Iowa land to row crops

Using modern mapping and geospatial technologies, the Environmental Working Group has identified the leading counties in the conversion of wetlands and highly erodible grassland and prairie to row crops.

Iowa has just two of the wetland conversion “hotspot” counties, but 38 of its 99 counties are considered hotspots for the conversion of highly erodible land to corn and soybean production.

Encouraged by record grain prices and federal subsidies, farmers in the past five years have planted corn, soybeans and other crops on millions of acres of previously uncultivated land, eradicating wildlife habitat and exposing sensitive land to erosion and other forces of an increasingly unstable climate.

“Going, Going, Gone,” the report released Tuesday, is a followup to the group's 2012 report, “Plowed Under,” which found that from 2008 to 2011, 23.6 million acres of grassland, wetland and shrub land had been converted to row crops. The new analysis, which includes 2012 data, identifies specific areas where such conversions have been most extensive.

The report also correlates conversion hotspots with high crop insurance indemnity payments, contending that the availability of highly subsidized crop insurance provides an incentive for farmers to plant crops on marginal land.

Between 2008 and 2011, the average crop insurance payout for all 3,109 covered counties was $2.3 million per county.

In the 71 counties that lost more than 5,000 acres of wetlands and wetland buffers, however, the average payout was $10.1 million – more than four times the average, the report said.

The average payout in the 235 counties that were hotspots for conversion of highly erodible land was $5.8 million – more than twice the average, according to the report.

“These data strongly suggest that over-subsidized crop insurance policies are greasing the wheels of conversion to row crops,” said EWG Senior Vice President Craig Cox, co-author of the report.

The relationship between land conversion and crop insurance was not obvious in Iowa where 25 of the 38 counties with the highest crop insurance payouts were not among the 28 counties with the highest rates of conversion of highly erodible land to row crops.

Loss of wetlands has been most severe in South Dakota, North Dakota and Minnesota, which together account for 39 percent (731,000 acres) of all wetland and nearby habitat acres converted to row crops from 2008 to 2012, according to the report. In Iowa, only two counties, Adair and Taylor, were classified as wetland conversion hotspots – and each fell into the lowest range, with from 2,500 to 5,000 acres converted from wetlands to row crops.

Conversion to row crops on highly erodible land is more widespread, with 10 states – Texas, Colorado, Oklahoma, Montana, North Dakota, Iowa, Missouri, South Dakota, Kansas and Nebraska – accounting for 57 percent (3 million acres) of the acreage converted to row crops during that period, the report stated.

Thirty-eight of Iowa's 99 counties were classified as hotspots – a bloc of eight counties in northeast Iowa, which includes Delaware and Jones; two in far western Iowa; and a block of 28 counties in the lower four tiers, which includes Johnson, Iowa, Poweshiek, Washington and Keokuk.

Among Iowa counties, Taylor, Ringgold, Wayne and Adair had the highest conversion rate, in the range of 15,001 to 25,000 acres.

The report emphasized that the conversion of environmentally sensitive land in northeast Iowa threatens the Driftless Area, a region of valleys, bluffs and cold-water trout streams.

Based on its findings, the Environmental Working Group recommends that subsidies for crop insurance, currently about 60 percent of the premium cost, be scaled back in the next farm bill. The group also recommends that the next farm bill require farmers who accept federal subsidies to take basic measures to cut soil erosion on their most highly erodible fields and to refrain from draining wetlands.