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A growing ecological concern: grass-to-cropland conversion

As Minnesota and other states devise plans to acquire land for growing grasses in order to meet federal mandates for next-generation biofuels, vast Upper Midwest acreages already covered with grass are being rapidly converted to cropland.

The staggering rate of land conversion is a major setback for efforts to reduce emissions of carbon gases linked to climate change. One expert says the amount of carbon released as grassland is plowed up is equal to emissions from 15 million cars for a year.

It’s also seen as a huge threat to wildlife habitat — chiefly waterfowl and pheasants — at a time when the drying effects of climate change may be starting to diminish prairie marshlands, which provide critical wildlife nesting and protective cover.

Ironically, a key reason that millions of acres of Conservation Reserve Program (CRP) lands will be plowed for the first time in over a decade is that surging demand for corn to produce ethanol (increasingly seen as an undesirable biofuels feedstock) is running up commodity prices. The higher prices, in turn, are driving the rush to land conversion.

“This is really quite disturbing,” said Clarence Lehman, a University of Minnesota ecologist who’s part of a pioneering scientific team that’s won international notice for producing fuel from native prairie grass in ways far less damaging to the environment than growing corn for ethanol.

4.3 million acres over next 5 years

Citing U.S. Department of Agriculture (USDA) statistics, scientists at Ducks Unlimited (DU) said that in five years some 4.3 million acres of CRP land will convert from grass to row crops in the “prairie pothole region” covering large parts of Minnesota, Iowa, North Dakota, South Dakota and Montana. As farmers opt out of CRP contracts, in some cases they are also free to drain potholes that are considered important to waterfowl.

The amount of converted land is more than four times the expanse of northeastern Minnesota’s Boundary Waters Canoe Area. Not all the converted land is suitable for biofuels production, but all of it is quality wildlife habitat and serves to naturally soak up carbon. 
Nationally, the USDA estimates that 6.8 million CRP acres will be plowed up, and federal researchers say booming corn-ethanol demand is a key culprit.

Projected precentage loss of CRP acres across the prairie pothole region 2007-2012


Click on chart to enlarge

Timing seen as troubling
“We’re seeing the beginning of a situation that will only get worse,” said Scott Stephens, DU’s planning director in Bismarck, N.D. The timing is troubling to conservation and hunting advocates who earlier warned that the trend of a drying climate will likely erode the high value of potholes scattered throughout the Dakotas, forcing waterfowl to move east — where, as in western Minnesota, farming pressure has already drained over 90 percent of millions of potholes that once speckled the landscape.

Much of the converted grassland will be planted to wheat, especially in the far northern counties of Minnesota, North Dakota and Montana. But much of the converted land in eastern South Dakota, western Minnesota and Iowa is expected to be planted to corn and soybeans, and that’s “very bad for pheasants,” said Eran Sandquist of South Haven, Minn., a wildlife biologist with the nonprofit Pheasants Forever

Moreover, nearly all factors driving the land conversion are likely to remain in place for some time.

Ethanol produced from corn will grow to 9 billion gallons this year (more than double the rate of just two years ago) and will rise to 15 billion gallons in 2015 before leveling off — and by then gobbling up a third of the nation’s corn, directly competing with use of the crop for food and livestock feed.

Other factors affect demand

Demand for more U.S. cropland is also driven by weather-related production drops in Europe, Canada and Australia, and by the continuing weakening of the U.S. dollar that will push U.S. grain exports to over $100 billion this year, up from $61 billion in 2006. 

Prices for corn, soybeans and wheat are at historic highs (corn fetched $2 a bushel in 2005, but recently the Chicago Board of Trade put it at nearly $6; some predict it’ll jump by more than a dollar next spring), which is seen as a leading cause for supermarket food prices to climb faster than any time in two decades. 

As farmers and rural landowners know well, the high commodity prices also mean that crop rental rates are soaring.

Half of Minnesota’s 22 million acres of crops are grown on rented land, said Kurt Markham, marketing services director at the state’s agriculture department. Prime cropland rents for $200 an acre and “marginal” (less desirable) land goes for $100 to $120 an acre, Markham said. Removing marginal and “highly erodible” land from production was heralded by farm groups and conservation advocates when the 1985 Farm Act created the CRP. The law was intended to maintain competitive CRP rental rates, but that clearly has not happened.

Farmers can double rental income
Federal idle-land payments average $51 an acre, and farmers in today’s robust market can easily double their rental income by taking lands out of CRP. That’s exactly what they’re doing in droves and likely will continue as their 10-year contracts expire, predicts the USDA (PDF).
Farmers and grain exporters are among those enjoying the financial bonanza. 

But to researchers like the University’s Lehman and Joe Farigone at the Nature Conservancy in Minneapolis, converting grassland to cropland for corn ethanol is exactly the wrong biofuels approach. Farigone was part of a scientific team that reported earlier this year that converting grassland to corn actually produced more unwanted atmospheric carbon than it removed.

That’s because grasses and undisturbed soil hold (“sequester”) carbon, and can also act to cleanse the atmosphere of carbon that’s linked to climate change. Once disturbed — as with plowing — plants and soil decompose and release massive amounts of carbon.

The DU’s Stephens said that plowing up 4.3 million acres of Upper Midwest grassland as USDA forecasts would release as much carbon as emitted from 15 million cars in a year. This would blunt attempts by Minnesota and a host of other states to enact strategies to reduce carbon emissions.

“We’re deeply concerned about this,” said Mark Lindquist, biofuels program manager with the Minnesota Department of Resources (DNR). He said that while it’s “too early to panic,” state officials are closely studying the numbers to understand the full effect of cropland conversion.

DU puts the number at 608,000 acres in Minnesota alone, but Lindquist thinks that may be high — “although still in the wrong direction.” 

Pressure for cellulosic sources likely to grow
It’s among other concerns that Lindquist voiced about state efforts to proactively prepare for what is expected to be growing pressure for biofuels produced from cellulosic sources like the very grasses being plowed under with the CRP conversions.

Cellulosic ethanol is coveted by energy advocates because it comes from biomass that unlike corn requires no fertilizer or pesticides, little water, and no soil disturbance because the grass plants are perennials that require no annual plowing and sequester carbon in their massive root systems.

Gov. Tim Pawlenty requested $3.3 million for a “clean energy” pilot to provide incentives to farmers to grow perennial grasses for biofuels and to also provide other agricultural (cattle grazing) and ecological (wildfowl nesting) benefits. The Minnesota Senate had proposed $15 million for the same program, but the number was pared to zero before legislative conferees sent a bonding bill to Pawlenty earlier this month.

The only remaining funding proposal still alive in the Legislature is $750,000 for a two-year study by the University of Minnesota to demonstrate how prairie grasses can be grown for biofuels and at the same time managed to provide high-quality wildlife habitat. The study would occur on multiple plots of public land throughout the state. 

Also emerging is an effort to determine whether lands held in conservation reserve can also be managed for some agricultural purpose, such as well-managed livestock grazing, said the DU’s Stephens.

But those related efforts, while seen as important steps in moving the United States toward the lofty goal of producing 21 billion gallons of fuel from biomass like grasses, are miniscule in impact compared to the massive environmental and wildlife damage that is certain to occur as grassland is converted to growing crops, Stephens said.

Ron Way, a former reporter for several Midwest newspapers, covers the environment and energy issues. He can be reached at rway [at] minnpost [dot] com.

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Comments (1)

  1. Submitted by Jon Fure on 04/25/2008 - 02:24 pm.

    While the recently approved bonding bill did not include specific dollars for the RIM -Clean Energy program, it’s important to note that the Legislature and Gov. Tim Pawlenty included policy language that gives the Board of Water and Soil Resources new authority to amend existing conservation easements. That means that about 100,000 acres of grasslands on privately owned lands in existing RIM Reserve easements may be harvested for biofuels, provided that the landowner works with the board and the local Soil and Water Conservation District to establish a conservation plan that maintains the public benefits of the easement.

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