High Crop Prices Are Driving Land Use Change in the U.S. at an Increasing Environmental Cost

The USDA estimates that farmers in the U.S. will plant nine million more acres in corn in 2013 than they did in 2011, an increase of almost 10 percent. Over the same period, the USDA reports that four million acres have been taken out of the Conservation Reserve Program (CRP), a decline of almost 13 percent. These trends do not bode well for water quality, greenhouse gas emissions, and other critical environmental concerns. There are far more environmentally sustainable ways to meet growing demand for food, feed and renewable fuels than this. Will the next Farm Bill show the way?

Corn prices have moderated significantly in recent months from the August highs in the midst of last summer’s drought. However, they have risen again recently, as U.S. supplies have diminished and on concerns that last year’s drought is still not over for much of the country as farmers approach the next planting season. Read more in this recent news story from Bloomberg .

In turn, high crop prices are driving producers’ plans for the coming planting season. In the USDA’s January 11 World Agricultural Supply and Demand Estimates , the agency projects that producers will plant 97.2 million acres of corn in 2013, up from 91.9 million in 2012 and 88.2 million in 2011.

Where will all of this land come from? According to the same USDA projections, it is not likely to come from farmers switching land over to corn from other crops such as soybeans or wheat. Acreage planted for those crops is projected to increase or hold steady. Rather, much of the land likely will come from converting pastures, using land that has not been farmed recently or previously, and acreage returning to production from expiring CRP contracts.

The USDA Farm Service Agency reports that acreage enrolled under CRP contracts has declined by four million acres since the end of 2010, to a total of about 27.1 million acres at the end of 2012. Contracts on another 3.3 million acres are scheduled to expire in 2013. While many of those CRP contracts may be renewed for another term, with high crop prices, many farmers are likely to bet that they can make more money by returning the land to production than from the relatively low rent payments received from the CRP.

The expansion of crop acreage to marginally productive new land and the conversion of CRP land back to row crops does not bode well for water quality, greenhouse gas (GHG) emissions, or wildlife conservation. As reported in a previous SBFF post ( As Dead Zone in Gulf of Mexico Shrinks, Will Perennial Biomass Crops Help Keep It That Way? ), nutrient run-off from expanded corn and soy production in the Mississippi watershed has contributed significantly to ground and surface water pollution and the formation of an extensive, oxygen-depleted, dead zone in the northern Gulf of Mexico. Agriculture is estimated to contribute about half of the excess nutrient load. Opening millions more acres of land to mostly corn production will only compound the pollution.

In addition, this massive conversion of land is likely to result in significant GHG emissions – both from nitrogen oxide (N2O) emissions (with more than 300 times the global warming potential as CO2, according to the EPA ) from the increased use of nitrogen fertilizer across millions of additional acres, and from CO2 emissions, as carbon is released from plants and soils on former CRP land and other land not previously or recently planted. These potential impacts are reported in a 2011 article by Ilya Gelfand and colleagues, "Carbon debt of Conservation Reserve Program (CRP) grasslands converted to bioenergy production" , published in the Proceedings of the National Academy of Sciences . The authors estimate it will take 123 years to repay the carbon debt incurred from converting CRP grasslands to continuous corn production with conventional tillage (or 40 years for converting to continuous corn with no-till management).

There is a better way, of course, to improve farmers’ bottom lines, meet growing demand for food, feed and renewable fuels, and protect the environment. In an article released January 16, 2013, in the journal Nature , "Sustainable bioenergy production from marginal lands in the U.S. Midwest" , Gelfand and another group of colleagues find that growing and harvesting successional vegetation on marginal lands could produce as much or more renewable fuel per hectare as corn while also absorbing (rather than releasing) carbon from the atmosphere into plants and soils.

And, in another study released earlier this month, "Reduced nitrogen losses after conversion of row crop agriculture to perennial biofuel crops" , in the Journal of Environmental Quality , Candice Smith and colleagues report that deep-rooted, perennial biomass crops such as miscanthus, switchgrass, and mixed prairie plants can quickly reduce the flow of nitrate in groundwater and tile drainage systems and reduce N2O emissions into the air compared to corn.

This complemented a paper published in 2012 by Sarah Davis and colleagues, "Impact of second-generation biofuel agriculture on greenhouse-gas emissions in the corn-growing regions of the U.S." , published in Frontiers in Ecology and the Environment . Their modeling found that " If cellulosic feedstocks were planted on cropland that is currently used for ethanol production in the U.S., more ethanol (+82%) and grain for food (+4%) could be produced while at the same time reducing nitrogen leaching (−15 to −22%) and greenhouse-gas (GHG) emissions (−29 to −473%). The GHG reduction was large even after accounting for emissions associated with indirect land-use change. Conversion from a high-input annual crop to a low-input perennial crop for biofuel production can thus transition the central U.S. from a net source to a net sink for GHGs ."

This body of research raises critical issues and points to important opportunities as Congress resumes consideration of the Farm Bill this year. Current agricultural policies, such as commodity payments and crop insurance subsidies, along with growing global demand, are encouraging the expansion of crop production on marginal lands and discouraging much-needed conservation. The Farm Bills introduced in the House and Senate in 2012, in fact, would continue to reduce CRP acreage, and mandatory funding for the Biomass Crop Assistance Program (and other programs that encourage the development and use of sustainable biomass for renewable energy) would be much reduced from levels set in the 2008 Farm Bill. In short, many of the Farm Bill policy trends today are pointing in the wrong direction from the standpoint of environmental sustainability.

This growing body of research would point agricultural policy in a different direction, one in which farmers would be encouraged to expand conservation efforts, vastly improve nutrient management, and plant sustainable perennial biomass crops on marginal lands.