Carlisle says cover crops, perennials can steady farms ahead of super El Niño

Federal crop insurance leaves diversified farms without adequate protection

Writing in The Guardian’s opinion section, UC Santa Barbara associate professor Liz Carlisle said her 15 years visiting farms across the country has shown that operations that keep roots in the ground year-round — through offseason cover crops or perennial plantings — are better positioned to weather extreme events than neighbors whose fields lie bare in winter.

“As a researcher and writer who studies farmers’ responses to climate crisis, I have watched these heartbreaking events become all too common: flooded fields, missed planting windows, crops so drought-stressed they are not worth harvesting,” Carlisle wrote.

Some of the most resilient farms she has visited soak up heavy rains while neighbors have several inches of standing water, and achieve 80% of their average yields in years when they have seen just 40% of their average moisture, Carlisle wrote.

“Their secret is that they have gradually built up the carbon-rich organic matter in their soil, which allows the land to soak up and hold moisture like a sponge,” she wrote.

Forecasters have warned this year’s El Niño could become the strongest on record. The United States will not be hit as hard as Central and South America, the Caribbean, and southern Africa, but severe weather could still cause significant crop loss in some parts of the country, and heavy rains are forecast across the southern half of the United States this winter, Carlisle wrote.

Researchers Andrea Basche and Marcia DeLonge found that practices keeping roots in the ground year-round increase the space between soil particles by 8%, enough to make 16% more water available to plants during drought, Carlisle wrote. Cover crops can increase infiltration of heavy rain by 35% and perennials by 59% — enough, in many cases, to absorb a one-inch-per-hour rain event, she said.

If one-third of Iowa’s cropland grew perennials or cover crops, water runoff and flood frequency would decline by one-fifth in particularly wet years, Carlisle wrote, citing Basche and DeLonge’s findings. Iowa State University researchers have found that planting strips of native prairie between rows of corn and soy reduces sediment loss by 95%, she said.

Farmers incorporate these practices in various ways, according to Carlisle: planting fruit and nut trees in rows between annual crops; using berry bushes as hedgerows at field edges; experimenting with newly developed perennial grains; and grazing livestock on perennial pasture.

Adoption remains limited nonetheless. “Unfortunately, though, you won’t see many cover crops or perennials growing if you drive through the major farming regions of the country, because while they reduce farmers’ long-term risk of losing their crops, they often increase their short-term risk of losing income,” Carlisle wrote.

The federal crop insurance system contributes to that dynamic, she said. Insurance for commodity crops such as corn, soybeans, wheat and cotton is generously subsidized, so farmers can lose an entire harvest and still come out financially intact, according to Carlisle. Alternative crops such as elderberries or hazelnuts fall under a Whole Farm Revenue Protection program that “nearly everyone in the industry agrees is woefully inadequate,” she wrote. Additionally, it takes many years for perennials to mature and produce food, requiring farmers to seek other sources of support to tide them over during that period, Carlisle noted.

As the super El Niño develops, Congress is negotiating the farm bill, which Carlisle described as “a once-in-a-decade opportunity to invest in the resilience of our food system.” The Conservation Stewardship Program and the Environmental Quality Incentives Program support farmers adding cover crops and perennials, she said, but Senate Republicans have insisted on decreasing funding for those programs and have not entertained deeper reform to crop insurance. The bill has not advanced in part because of those disputes, according to Carlisle.

“Maybe this Super El Niño will be the nudge we need to finally invest properly in the resilience of American farms,” Carlisle wrote.

She is an associate professor of environmental studies at UC Santa Barbara, the author of “Healing Grounds: Climate, Justice, and the Deep Roots of Regenerative Farming,” and co-editor of “Living Roots: The Promise of Perennial Foods.”