Federal agricultural and energy policies of the past decade may have adverse effects on conservation, according to a recent study from the University of Wisconsin.
Related: Tree 'cover crops' clean up streams
The paper suggests that policy thought to be good for the environment can sometimes have undesirable consequences.
Regional satellite-based studies suggest that the U.S. landscape could be experiencing the greatest transformation to cropland since the "fencerow-to-fencerow" farming era of the 1970s, and the Dustbowl of the 1930s.
The study found that between 2008 and 2012, an estimated 7.34 million acres of land was converted to crop production.
Land sources of recently converted cropland varied within the study, but grasslands pulled ahead as the source of most new cropland at about 77%. Eleven percent of the land was converted from shrub land and forest, 8% from idle land, and 4% from wetlands or other land. The study doesn't take into account conversions of 15 acres or smaller.
In 31 of the 47 states that saw conversion, corn was the first crop planted on newly converted land. Corn and soy were the most frequently planted crop on newly cultivated land in the agricultural belt of the Midwest.
The study also suggests that an estimated 42% of the expansion of cropland may have come from land leaving the Conservation Reserve Program, which raises another policy question.
The CRP pays a yearly rental amount to farmers in exchange for removing environmentally sensitive land from agricultural production.
According to USDA, landowners with expiring contracts have various options for managing the land aside from returning it back to crop production, including converting it to wildlife habitat or conservation easements. Both actions would provide for the continued protection of natural resources and benefit conservation.
"These land-use changes often occur in areas where we need permanent vegetation such as trees and grasslands to protect our streams and rivers," said Bob Atchison, rural forestry leader for the Kansas Forest Service at Kansas State University. "This vegetation improves our water quality and sustains our water supplies."
According to the University of Wisconsin study, loss of shelterbelts and windbreaks is also occurring throughout the Great Plains due to cropland expansion.
"The research supports that shelterbelts can actually increase crop yields and are often the last conservation practice to prevent soil erosion during a drought," Atchison said.
A conclusion suggested by the results of the Wisconsin study was that removal of adverse incentives, and proper implementation of U.S. agricultural and biofuel policies would go a long way toward achieving protection of streamside forests and shelterbelts from cropland conversion.
Source: Kansas State University