Letter from the Land-April 8, 2002

10 Tons of Graphic Material

By Brian DeVore

NEW PRAGUE, Minnesota—Recently, I got a graphic look at what happens when the land is farmed in two very different ways. Piled before me was a mound of soil-enough to fill a five-gallon bucket. Dwarfing it was a mountain of dirt that just moments before had filled a dump truck. The larger pile-about 10 tons-represented how much soil was violently removed within a few hours from each acre of a farm field near New Prague during a single intense rainstorm. On a field just up the road from New Prague near the town of Jordan, that same storm loosened just 53 pounds of soil per acre-enough to fill the five-gallon bucket. Bob Austin, a New Prague-area earth moving contractor who is passionate about soil conservation and duck hunting, helped me set up these two piles of soil to get a clear picture (literally and figuratively) of the difference in erosion rates on the two fields, which were part of separate University of Minnesota runoff studies. Bob's passion for the land manifests itself in an outspoken anger toward what he sees as one of the biggest threats to soil and wetlands in the Midwest: tax-funded subsidization of large-scale, unsustainable farming. Bob never passes up a chance to go public with his feelings on this issue, even speaking out at farmer meetings where his opinions are often not welcome. So it was no surprise that when we finished arranging the two piles of soil, he quickly got to the point: "That's just plain gross."

Losing 10 tons of soil off of a single acre in a matter of hours isn't just gross, it's obscene. It's more than double the national average erosion rate for one year and it will take centuries to replace that soil. Unfortunately, states like Minnesota have become familiar with this kind of erosion in recent years. In fact, 29 percent of our crop fields are "excessively eroding," says the USDA's Natural Resources Conservation Service (five tons of soil loss per acre, per year is considered "tolerable" by USDA, but many scientists question whether even that's sustainable).

"Our rich, black, deep and uniform soils will only be a memory of the past if this rampant erosion is not controlled," noted University of Minnesota soil scientist Gyles Randall recently.

But it doesn't have to be that way, as the bucket's worth of soil proves. It comes down to how much live vegetation is covering the soil at key times in the growing season. During the storm, which took place on a late June evening, the field near Jordan was growing oats and alfalfa. Part of the field was also blanketed with grass, which was being rotationally grazed by a dairy herd. All this provided a thick, uniform ground cover. The New Prague field, in contrast, was growing corn under a moldboard-plow tillage system, which provides plenty of room between plants where raindrops can hit bare ground.

These results have major implications for agriculture. But ultimately, anyone who pays taxes-upstream, downstream, farmer, non-farmer, whoever-should pay heed to the role a crop field can play in water quality. That's because the federal government rewards farmers financially for planting corn, soybeans and a handful of other commodity crops. This has carpeted the rural landscape with a cropping system that often erodes soil at an unsustainable rate. That soil, and any contaminants that are along for the ride, ends up in our lakes, streams and reservoirs. The watershed where the New Prague and Jordan farms are located is a leading source of the Minnesota River's sediment contamination. The Minnesota, in turn, is one of the Mississippi River's major polluters. What takes place on those farm fields affects more than the local creek.

Now consider the Jordan farm field that has diversified into grass, alfalfa, and small grains-enterprises that aren't considered worthy of agricultural subsidy payments, and yet are proven soil savers. In effect, government programs are saying that soil-building systems-even a little agronomic diversity-is bad for society.

A more sustainable approach to farm policy doesn't mean eliminating row crops in the Midwest. But it could go a long way toward removing barriers to true on-farm diversity and dumping this senseless "favorite son" approach to paying farmers for corn and soybean production no matter what the cost. And policy that rewards diversity would recognize that making significant gains in conservation doesn't always mean idling working farmland.

But as the soil-stained snows recede and the 2002 planting intentions reports begin to emerge, it's clearer than ever that corn and soybeans rule here in the Midwest. That means more piles of excess grain no one wants to buy, and, trailing not far behind, heaping truckloads of eroded soil no one wants to look at.

Brian DeVore is the editor of the Land Stewardship Letter. The Land Stewardship Project encourages distribution and republication, with proper credit, of this commentary. For more information on the soil runoff studies mentioned here, go to http://www.landstewardshipproject.org/lsl/lspv19n2.html#coverstory.