Wednesday, February 10, 2016

Cover Crops, a Farming Revolution With Deep Roots in the Past

... Concern about the soil quality of the family’s fields had nagged at [Mark Aronson] for some time....  What he learned about the benefits of cover crops gave him hope.

... Planting some noncommercial crops seemed an antiquated practice, like using a horse-drawn plow. Cover crops had long been replaced by fertilizers. Still, [the] soil ... texture was different, not as loamy as it had once been, and a lot of it was running off into ditches and other waterways when it rained.
So in 2010 the family decided to humor Mark by sowing some 1,200 acres, which Mark describes as highly eroded farmland, with wheat cleanings and cereal rye. Additionally, they spread some cover crops to eroded areas in a few fields.

The next spring, [his brother] Doug had to admit that the soil texture on that strip was better. And the water that ran off it during a rainstorm was clear, a sign that the roots of the cover crops were anchoring valuable topsoil in place.

But Doug didn’t become a believer until 2013, when the family was grappling with a terrible drought. ... Now some 13,000 of the 20,000 acres that the family farms across nine counties are planted with cover crops after harvesting, and farmers around them are beginning to embrace the practice.

Cover crops are coming back in other areas of the country, too. The practice of seeding fields between harvests not only keeps topsoil in place, it also adds carbon to the soil and helps the beneficial microbes, fungus, bacteria and worms in it thrive.
Cover cropping is still used only by a small minority of farmers. When the Agriculture Department asked for the first time about cover cropping for its 2012 Census of Agriculture report, just 10.3 million acres — out of about 390 million total acres of farmland sown in crops — on 133,124 farms were planted with cover crops.... In an annual survey of about 1,200 farmers, the mean acreage reported as being sown in cover crops was 259 in 2014. That was double the mean reported by respondents in 2010, though results are not directly comparable because different farmers may have been involved in the surveys, said a spokesman for the Sustainable Agriculture Research & Education, a federal government program, which conducted the survey.
Interest in cover crops is coming from buyers, too. Dan Barber, a prominent chef who uses locally grown foods, has championed incorporating cover crops like clover and millet into cuisine as a way of encouraging farmers to grow them.
One measure of how rapidly the practice is growing is the booming demand for cover crop seeds. 
Modern farming practices like applying fertilizer and herbicides and not tilling their fields, or “no till,” have helped farmers increase yields and reduced labor, but they have also unintentionally interfered with root systems, increased erosion and disrupted underground microbial activity and insect life that are vital to plant and soil health. ...
Young soybean plants thrive in and are protected by the residue of a wheat crop
Today, all 5,000 acres [Dan DeSutter] farms are sown after the harvest of corn and soy with a mixture of as many as 12 different crops, including sunflower, sorghum, buckwheat, turnips and hairy vetch, each of which delivers a different benefit. Most die off in the winter and decompose, leaving behind a rich layer of organic matter that gradually sinks into the earth. Farmers use a planter or seed drill to punch the seeds for their cash crops into the decaying cover crop.

Before cultivation, Indiana was blanketed in prairie grasses and forest, and the carbon content of the soil was as high as 10 percent in places. Today, after decades of tillage, which moves carbon from the soil into the atmosphere, and monocropping, the level on many farms is below 2 percent, Mr. Fisher said. Cover crops restore organic matter back into the soil, at a rate of about 1 percent every five years.

“As we put carbon back into the soil, it gives us a bigger tank to store water naturally,” Mr. DeSutter said. “This is one way we build resilience into the system.”

The adoption of cover cropping has been especially rapid in Indiana — about one million of the 12.5 million acres of farmland there are planted with cover crops between harvests. 
Rodney Rulon, whose family farms 6,200 acres in northeastern Indiana and plants about four-fifths of them with cover crops.... He has found, for instance, an increase in organic matter and higher corn yields — an average of 12.8 bushels an acre more in one of his cover-cropped fields.... “You really start seeing a difference in your soil within two or three years,” Mr. Rulon said.

The Rulons spend about $100,000 a year on cover crop seed, or about $26 an acre. But they also saved about $57,000 on fertilizer they no longer needed, and bigger yields mean about $107,000 in extra income.

Including the value of improved soil quality, less erosion and other improvements, Mr. Rulon estimates that Rulon Enterprises gets about $244,000 of net economic benefit from cover crops annually, or a little more than $69 an acre.

The federal government is mulling ways to persuade farmers to adopt cover cropping. There is a small subsidy system; Rulon Enterprises, for instance, gets $40,000 to help offset the cost of cover crops and support other conservation practices.
By Stephanie Strom
The New York Times
February 6, 2016

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