Planting Crops - And Carbon Too

President Biden says farmers can adopt agricultural methods that help fight climate change.

Maryland farmer Trey Hill pulled in a healthy haul of corn last fall and then immediately planted rye, turnips, clover and other species, which are now spreading a lush green carpet over the soil. While his grandfather, who started the family farm along the Chesapeake Bay, always planted in the spring in a clean field, in Hill’s approach to farming, “you never want to see the ground.” And you never plough or till it.


As the winter cover crops grow, they will feed microbes and improve the soil’s health, which Hill believes will eventually translate into higher yields of the crops that provide his income: corn, soybean and wheat.


But just as importantly, they will pull down carbon dioxide from the atmosphere and store it in the ground. Hill is at the cutting edge of what many hope will provide not just a more nature-friendly way of farming, but a powerful new climate solution, reports The Washington Post.


In early 2020, he became the first seller in a privately run farmer-focused marketplace that paid him $115,000 for practices that, over the past few years, had sequestered just over 8,000 tons of carbon in the soil. The money came from corporations and individuals who want to offset carbon dioxide produced by their activities. Hill used the proceeds to buy equipment he hopes will allow him to squirrel away even more of the planet-warming gas.


If farmers throughout the world adopted similar “regenerative” methods, experts estimate they could sequester a sizable chunk of the world’s carbon emissions. The idea has been endorsed by soil scientists, a slew of food industry giants and, recently, President Biden.


Researchers and companies are now racing to reduce the scientific uncertainties and win over skeptics. Many scientists are confident that farming can be adapted to build carbon into soils, said Deborah Bossio, a soil scientist at the Nature Conservancy, an environmental organization. “We know how to do it,” she said.


Agriculture has done a masterful job of feeding the world’s burgeoning population. It has been less wonderful for the climate. For thousands of years, plowing has mixed underground carbon-containing compounds with atmospheric oxygen, creating carbon dioxide, the main greenhouse gas that is driving global warming.


As scientists came to appreciate the threat posed by climate change over the past few decades, some wondered whether carbon already in the atmosphere could be captured and returned to the soil. A team led by Bossio estimated in early 2020 that if soil was protected and replenished globally, it could provide nearly 10 percent of the planet's carbon dioxide drawdown.


Soil carbon building practices, loosely gathered under the term “regenerative agriculture,” have been practiced for decades, or centuries in some places. Planting without tilling the soil took off after the devastating Dust Bowl in the 1930s spurred a search for ways to avert further soil loss, and the practice now includes more than a fifth of U.S. farmland.


Hill, who farms 10,000 acres, admitted he got into cover crops purely because the state paid him. “We had no intent of doing it for climate,” he said.


But he has since become a true believer. He now mixes rye and other fast-growing grasses with legumes such as clover and lentils, whose roots host nitrogen-fixing bacteria. He also plants root crops such as radishes and turnips to loosen and aerate the soil. While most farmers kill their cover crops in March, as soon as the state allows, Hill lets the plants grow taller than he is, to maximize root mass and carbon gains. He kills them just before planting his cash crop in May.


“The longer the cover crop is alive, the better off we all are,” he said. “Soil health,” he said, “should be the solution to climate change.”


If farmers were paid for the carbon accumulating in their soils, they would have greater incentive to adopt climate-friendly practices, Hill said.

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