Later On

A blog written for those whose interests more or less match mine.

Can American soil be brought back to life?

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Jenny Hopkinson writes in Politico:

Four generations of Jonathan Cobb’s family tended the same farm in Rogers, Texas, growing row upon row of corn and cotton on 3,000 acres. But by 2011, Cobb wasn’t feeling nostalgic. Farming was becoming rote and joyless; the main change from one year to the next was intensively planting more and more acres of corn and soy, churning up the soil and using ever more chemical fertilizers and herbicides to try and turn a profit.

“I’d already had the difficult conversation with my dad that he would be the last generation on the farm,” Cobb said.

While looking for a new job, Cobb stopped into a local office of the U.S. Department of Agriculture to pick up some paperwork. That day, the staff was doing a training session on soil health. He stayed to watch and was struck by a demonstration showing a side-by-side comparison of healthy and unhealthy soils.

A clump of soil from a heavily tilled and cropped field was dropped into a wire mesh basket at the top of a glass cylinder filled with water. At the same time, a clump of soil from a pasture that grew a variety of plants and grasses and hadn’t been disturbed for years was dropped into another wire mesh basket in an identical glass cylinder. The tilled soil–similar to the dry, brown soil on Cobb’s farm—dissolved in water like dust. The soil from the pasture stayed together in a clump, keeping its structure and soaking up the water like a sponge. Cobb realized he wasn’t just seeing an agricultural scientist show off a chunk of soil: He was seeing a potential new philosophy of farming.

“By the end of that day I knew that I was supposed to stay on the farm and be part of that paradigm shift,” Cobb said. “It was that quick.”

The shift he’s talking about is a new trend in agriculture, one with implications from farm productivity to the environment to human health. For generations, soil has been treated almost as a backdrop — not much more than a medium for holding plants while fertilizer and herbicides help them grow. The result, over the years, has been poorer and drier topsoil that doesn’t hold on to nutrients or water. The impact of this degradation isn’t just on farmers, but extends to Americans’ health. Dust blowing off degraded fields leads to respiratory illness in rural areas; thousands of people are exposed to drinking water with levels of pesticides at levels that the Environmental Protection Agency has deemed to be of concern. The drinking water of more than 210 million Americans is polluted with nitrate, a key fertilizer chemical that has been linked to developmental problems in children and poses cancer risks in adults. And thanks to some modern farming techniques, soil degradation is releasing carbon—which becomes carbon dioxide, a potent greenhouse gas—instead of holding on to it. In fact, the United Nations considers soil degradation one of the central threats to human health in the coming decades for those very reasons.

Now, some farmers and soil scientists are realizing that for the health of both people and farms, the most important thing you can do is look at soil differently—seeing topsoil as a living thing itself, which can be tended and even improved. Good soil is alive with a host of delicate organisms, many of them microscopic, producing structure and nutrients. As long as they’re thriving, soil can better absorb and retain water and feed plants and control pests. But when they die off, because they’ve been churned up and exposed to the sun and air or smothered with chemicals, the soil gradually becomes little more than powdered minerals.

Science and farming techniques have been evolving—in part thanks to the Agriculture Department’s Natural Resource Conservation Service, where Cobb saw that demonstration in 2011 that changed his worldview. But the change isn’t coming easily. Even as some farmers move toward more holistic soil management, they’re running into friction–from the culture of farming, from the business of agriculture and—ironically—from some federal policies that encourage them to stick to the same old farming approach that got them here.

AMERICA USED TO be famed for its rich and fertile topsoil. Prairie and forests were virtually untouched when settlers first started dividing land into fields across the Southeast and Midwest, making for rich dark soil in which to grow food and fiber.

Since the invention of the plow, farming has focused on disrupting the soil to make it productive. Most farming methods, whether conventional or organic, are based on “tillage” – the premise that to plant crops and control weeds and other pests, the soil must be broken up and turned over, then amended with chemical fertilizers or organic compost to boost fertility. And it worked for a long time.

But tilling, it turns out, kills off many of the microorganisms that build the soil. It churns up their habitat and exposes them to air; it also makes it easier for soil to be washed off the land by rain and wind. Over time, the damage has built up: More than 50 percent America’s topsoil has eroded away. In areas of the Southeast, the country’s original breadbasket, it’s almost all gone.

Soil, at its base, is 50 percent gas and water, and roughly 45 percent minerals such as sand, silt and clay. The remainder is organic matter—decomposing plants and animals. For being such a small portion of dirt, organic matter plays a huge role. It serves as food for microorganisms that do everything from store water to provide nutrients for plants and control pests. Researchers are learning more and more about the exchange between plants and fungi, bacteria and other organisms in the soil, said Robert Myers, a professor of soil sciences at the University of Missouri. . .

Continue reading.

Do read the article. Some fascinating photos included with it.

Written by LeisureGuy

14 September 2017 at 10:51 am

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