Mimic nature to harvest benefits of healthy soil, expert says
By Michelle Banks
World Soil Day
Bartt McCormack uses cover crops and no-till to improve yields on his Tennessee farm.
In the minds of many, a freshly tilled field is picturesque – clean and ready for the next planting. But according to a soil health expert, what looks good to the eye, isn’t always good for the soil – or a farmer’s bottom line.
Today, on World Soil Day, USDA’s Natural Resources Conservation Service is celebrating the importance of healthy soils and sharing how farmers and ranchers can help care for it through conservation practices like no-till.
“Nature does not till,” said Ray Archuleta, conservation agronomist with NRCS. “Which begs the question: Why do we?”
When soil is heavily tilled, the stalks from the previous crop are chopped, and the top several inches of soil structure are disturbed. Conventional thought suggests this fluffing action allows for better seed placement, but Archuleta said that no-till systems, especially when combined with cover crops, are better – and lead to healthier, more drought-resistant soil.
Archuleta, who works at the agency’s East National Technology Center in Greensboro, N.C., said no-till has significant financial benefits for producers, too.
“No-tillage can save thousands of dollars every year in fuel, labor and equipment maintenance,” Archuleta said. “The key is to let the soil organisms do the work.”
Tillage disrupts soil ecology
Archuleta compares soil aggregates to the soil’s lungs and circulatory system. Aggregates provide oxygen for roots, increase pore space for water infiltration and reduce erosion.
Aggregates are also micro-ecosystems for housing bacteria, fungi and other soil organisms that are responsible for breaking down residues and soil nutrient cycling. The majority of these organisms are housed in the upper few inches of the soil – the top soil that is being damaged by tillage.
Any tillage causes organic matter to decompose, resulting in loss of soil carbon.
Instead, Archuleta recommends no-tillage and adding fresh organic matter, such as manure, compost, and root and plant residue from living, diverse cover crops. Soil organisms use this as food to create healthy, biologically active soil ecosystems.
“Soils with healthy ecosystems cycle water and nutrients more efficiently and increase overall soil function to buffer against extreme drought and flooding,” Archuleta said.
Rather than conventional tillage, Archuleta suggests farmers use cover crops to address functional soil issues like compaction. “Tillage vegetables, such as radishes, grow deep into the soil to break apart compacted areas,” he said. “Annual ryegrass, crimson clover, winter cereal rye, oats and other cover crops also do a good job of reducing compaction and retaining moisture in the soil.”
No-till, cover crops pay for Tennessee farmer
Tennessee grain farmer Bartt McCormack has refrained from tilling — instead using no-till planting — for more than 35 years. He knows first-hand why no-till with cover crops has created a favorable soil ecosystem. They’ve had a positive impact on his bottom line, he said.
“We’re a 90-95 percent no-till operation,” he said. “When you start pulling iron over 6,000 acres, it takes a lot of labor and a lot of fuel.”
McCormack grew up using tillage on the family farm, but after enrolling in NRCS programs, the farm began implementing no-till on more and more acres.
But McCormack cautions there is a process in transitioning to a no-till operation. He advises that farmers have to re-tool and change management practices on herbicides and rotations, but most importantly, they need to have an open mind at the possibilities that no-till with cover crops can bring.
“It’s not like changing a pair of pants,” he said.
McCormack has seen a boost in yields since he made the transition to no-till. “I’ve seen a 60 bushel difference in yield. That’s a tremendous amount.”
On fields where he also planted cover crops, McCormack said his yields were event better. “Looking back, plowing up my fields was reducing my yields.”
Like a growing number of farmers across the nation, McCormack is sold on the benefits of improving soil health. He plans to continue experimenting with different varieties and combinations of cover crops, including planting multiple species on nearly all of his 6,000 no-till acres this fall.
To learn more about healthy soils, visit our “Unlock the Secrets in the Soil” webpage or visit local NRCS office.