Land doesn’t get better than on the Rock Prairie

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By MARCIA NELESEN
The Janesville Gazette

JANESVILLE, Wis. (AP) — A glacier that moved south from Canada about 13,000 years ago ground to a halt across northern Rock County.

As the mile-thick slab of ice melted, sand and gravel washed onto the southern plain known now as the Rock Prairie.

Later, windblown silt called loess settled over the sand and gravel. The sediment probably came from the Mississippi River Valley, at that time a broad floodplain.

Over the years, prairie vegetation took root and formed rich, dark topsoil, normally 4 to 5 feet deep but sometimes up to 6.

The soil‘s crumbly texture allowed roots to breathe and water to percolate. At the same time, a mix of clay under the soil captured moisture for plants to grow during dry periods.

Similar soils are found in only a few other places in the world, experts say.

The combination of soil and climate, however, sets the Rock Prairie apart, said Fred Madison, professor in the Department of Soil Science at UW-Madison.

He calls the prairie the “perfect storm” for crop production.

“The setting in the Rock Prairie is as good as any in the world. Everything is there,” he said.

“In southern Wisconsin, we get in the summertime an inch of rainfall a week. Guess what a corn crop takes? An inch of rain a week.”

Are the growing conditions on the prairie the best in the world?

“That may be a bit egocentric, but I certainly as a loyal Wisconsin native have no problem claiming it,” Madison said. “It’s safe to say the combination of climate and soil and vegetation and everything we have on the Rock Prairie is very, very unique.

“All the good stuff happens in Rock County.”

Madison is not alone in using “perfect” to describe the prairie’s growing conditions.

Jim Stute, crops and soils agent for UW Extension, calls the prairie a “perfect confluence” of soil, flat land and climate.

The Rock Prairie generally extends from County A to the state line. It is bordered on the west by Interstate 39/90 and extends east into Walworth County.

The Rock Prairie’s plano silt loamone of the best soil types in the worldcovers about 8 percent of Rock County’s land, said Norm Tadt, senior conservation specialist with the Rock County Land Conservation Department.

What are the prairie’s virtues?

— It’s young soil, in a geological sense. It’s chock-full of the fresh minerals and nutrients needed for crop growth. Africa, by contrast, has old land surfaces and worn-out soil.

— It gets enough rain. Southern Wisconsin gets more than is needed to grow crops, so the groundwater is replenished. That is no small factor. Moving west, the ratio changes. Sections of the Great Plains are reverting to pasture because irrigation there is depleting an ancient aquifer.

— The winter. The soil gets a break from the constant attack of bacteria and fungi. The cold breaks the pest cycles. The subsoils rebuild their moisture. The freezing and thawing restores the soil structure.

— It’s contour. The land is flat, perfect for farming.

Madison said the challenge is to recognize the prairie as a precious and irreplaceable natural resource.

“It’s the same we face everywhere in that the very best soils in any location are the very best soils for everything: best for septic, best for highways, best for building houses and growing crops,” Madison said.

“As you look over the prairie, it looks sort of endless,” Madison said. “It’s not endless. That’s the key thing to remember.”

Madison recalled similar soils in Oconomowoc in an area known as the Pabst Farms. The soil was a bit shallower than on the Rock Prairie, but it was beautiful prairie soil, Madison recalled.

It has been lost to development, and that is a huge, tragic loss, he said.

“Those are decisions we made. Once they’re gone, you don’t bring them back. It’s irreplaceable. With all my years of being in soil science, I can’t tell you how to re-create them.

“When you have agricultural land the quality of … the Rock Prairie, even though it may not be something that looks like the biggest dollar winner, you have to look at it long term and the potential that those soils have.”

If properly managed, the production quality of the land on the Rock Prairie is among the world’s best.

“That’s very important,” he said. “We don’t have a lot of soils that perform that well.”

Madison predicts that Janesville’s proximity to metropolitan areas will become increasingly important as more people buy locally because they want to know where their food is grown.

“The fresh food market is just huge,” Madison said. “To have diversified agriculture in the southern part makes a boatload of sense.

“We have tough times now, but we should continue to be level headed as we think about planning.”

Information from: The Janesville Gazette, http://www.gazetteextra.com