Monday, May 9, 2011

Losing Ground - Washing Away the Fields of Iowa

Executive Summary
Across wide swaths of Iowa and other Corn Belt states, the rich, dark soil that made this region the nation’s breadbasket is being swept away at rates many times higher than official estimates.

That is the disturbing picture revealed by scientists tracking soil erosion in Iowa after every storm that hits the state and producing an unprecedented degree of precision in soil erosion estimates. The Environmental Working Group corroborated the scientists’ findings with aerial surveys that produced striking visual evidence of the damage.

In April 2010, USDA’s Natural Resources Conservation Service (NRCS) released data estimating the rate of soil erosion on agricultural land in the United States. On the surface, the data from the 2007 National Resources Inventory (NRI) were reassuring. Erosion in Iowa averaged 5.2 tons per acre per year, only slightly higher than the allegedly “sustainable” rate of five tons per acre per year for most Iowa soils — the amount that can supposedly be lost each year without reducing agricultural productivity. Across the entire Corn Belt, erosion averaged only 3.9 tons per acre per year, according to the NRCS data.

There is compelling evidence, however, that soil erosion and runoff from cropland is far worse than these estimates suggest. Indeed, it appears that the nation is losing ground in the decades-old fight to gain control over this most fundamental and damaging environmental problem in agriculture.

In some places in Iowa, recent storms have triggered soil losses that were 12 times greater than the federal government’s average for the state, stripping up to 64 tons of soil per acre from the land, according to researchers using the new techniques. In contrast to the reassuring statewide averages, the researchers’ data indicate that farmland in 440 Iowa townships encompassing more than 10 million acres eroded faster in 2007 than the “sustainable” rate. In 220 townships totaling 6 million acres, the rate of soil loss was twice the “sustainable” level.

The aerial survey conducted by EWG in the spring of 2010 indicated that soil erosion and runoff are likely far worse than even the ISU numbers suggest, because researchers’ current models do not account for the effect of widespread “ephemeral gullies.” During heavy rains, these gullies reappear rapidly where farmers have tilled and planted over natural depressions in the land and form “pipelines” that swiftly carry away the water the earth cannot absorb.

The ISU data and EWG’s survey reinforce long-standing doubts about the very system used to describe the so-called “sustainable” level of erosion — how much soil loss the land can tolerate before it loses its ability to sustain a healthy crop. These “T values” are gauzy estimates at best, and there is substantial and growing evidence that they greatly overstate the ability of cropland to remain fertile in the face of the ravages of soil erosion and water runoff, especially at a time when a warming climate is producing ever more frequent severe storms. For lack of a better alternative, however, this report’s discussion does use T values as a point of reference.

The runoff from vulnerable farmland not only washes away soil – the fertile legacy of thousands of years of geological processes — but also carries with it a potent cargo of fertilizers, pesticides and manure that flows into local creeks and streams and eventually into the Mississippi River. Ultimately it ends up in the Gulf of Mexico, generating the notorious dead zone — a zone of depleted oxygen that suffocates marine life when it forms each year.

The accelerating soil loss is being driven by federal farm policies that encourage and subsidize sowing commodity crops on even the most fragile terrain, as well as by intense rainstorms that occur with increasing frequency as Earth’s climate warms. The recent history of severe springtime flooding across the Midwest is but the most immediate consequence of this trend, but the impact on the region’s agriculture and environment will be the greater and more lasting disaster.

Meanwhile, efforts to curb soil erosion, many of them launched under a 1985 law that temporarily produced a 40 percent reduction in erosion and runoff from the most vulnerable cropland, have faltered badly. The backsliding began in 1996 when Congress made an abortive attempt to phase out the farm subsidy program, along with its soil conservation requirements. In the end, lawmakers instead returned to plowing billions into farmers’ hands through ad hoc disaster payments, ultimately restoring the earlier farm subsidy program with a vengeance by 2002.
EWG’s findings are an urgent reminder that the Corn Belt’s carpet of immensely fertile soil, a resource that accumulated over millions of years before European settlers introduced organized agriculture, is not inexhaustible. From the Dust Bowl of the 1930s to the barren moonscapes of today’s Haiti and Madagascar, history is littered with evidence that what nature has provided, unwise practices and policies can rapidly squander.

Today, the soil erosion problem in Iowa and nearby states is nowhere near the scale of those historic calamities, but the data show that the situation is getting worse. Chronically underfunded voluntary conservation programs are failing to blunt the damage caused by federal policies that push farmers to plant crops fencerow to fencerow. Between 1997 and 2009, the government paid Iowa farmers $2.76 billion to put conservation practices in place. It paid out six times as much — $16.8 billion — in income, production and insurance subsidies that encouraged maximum-intensity planting, not conservation. Across the Corn Belt, the gap was even greater — $7.0 billion for conservation and $51.2 billion for income, production and insurance subsidies.
The $18.9 billion spent to subsidize expansion of the corn ethanol industry, along with misguided federal mandates to produce increasing amounts of ethanol, further increase the pressure to intensify production.

To turn this situation around, the US Department of Agriculture (USDA) must step up enforcement of the groundbreaking 1985 farm bill provision — called conservation compliance — that required producers to take action to conserve soil in order to stay eligible for billions in farm subsidies. USDA must increase its annual inspections to determine whether producers are maintaining the required soil conservation practices and also make full use of its authority to impose graduated penalties on farmers who fail to keep the required practices in place.

In addition, EWG believes that Congress must:
* Reopen and revise all the legacy conservation compliance soil conservation plans approved and applied before July 3, 1996, requiring that they reduce erosion to a truly “sustainable” level and prevent ephemeral gully erosion on highly erodible cropland.
* Require treatment and/or prevention of ephemeral gully erosion on all agricultural land — not just highly erodible land — owned by producers or landlords receiving income, production, insurance or conservation subsidies.
* Require vegetative buffer zones at least 35 feet wide between row crops and all lakes, rivers, and smaller streams.
* Require all producers participating in existing or new crop and revenue insurance programs to meet conservation compliance standards.
* Ensure that farmers who convert native prairie or rangeland to row crops are not eligible to receive income, production, insurance or conservation subsidies on those acres.
* Adequately fund the USDA technical staff — out of funds provided for programs covered by compliance provisions — needed to plan and implement the required conservation practices and to conduct annual inspections to certify that those practices are in place.

By Craig Cox, Andrew Hug and Nils Bruzelius
Also see a New York Times editorial based on the study at:

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