Cover Crops, Limited-Till Championed By Delta Farmer

JOHN LOVETT

FAYETTEVILLE, ARKANSAS

For Adam Chappell, cover crops and limited tillage practices have not only decreased irrigation, pesticide and synthetic fertilizer use but also improved soil quality and decreased water runoff.

Chappell, a fourth-generation tenant farmer in Cotton Plant, spoke to over 200 attendees of the Arkansas Agriculture, Forests, and Water Conference at the Don Tyson Center for Agricultural Sciences in Fayetteville. The conference was co-hosted by the Arkansas Water Resources Center, July 16-18.

The Arkansas Water Resources Center is a part of the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas System Division of Agriculture. It provides water quality data to support municipalities, state agencies and watershed groups as they develop and implement management plans and practices. Located in Fayetteville, the center is part of a national network of water research centers investigating irrigation, wastewater disposal, groundwater, erosion, pollution and ecosystem problems.

During a session focused on water myths and disinformation, Chappell spoke about his farming operation and his decision to adopt cover crops and limited tillage.

Chappell grows soybean, corn, rice and cotton on 2,500 acres in Woodruff County and started using cover crops and limited tillage in the fall of 2009 and spring 2010. Since 2016, he said he has not had to apply synthetic phosphorus and potassium fertilizer, and his nitrogen fertilizer application is down 35 percent. Due to weed suppression from the cover crops, he said his need for herbicide is only 20 percent of what it used to be. Since the cover crops retain moisture, he said his need for irrigation has dropped 40 percent.

Chappell noted a similar improvement in insect pest management.

“The cover crop is a habitat for birds, pollinators and predators, so in turn, my pest pressure each year is limited because I have a robust predatory insect population ready to eat anything that’s going to cause me a problem,” Chappell said.

Water quality benefits

While benefits of cover crops and no-till include less inputs like fertilizer, irrigation and pesticides, Chappell also showed how land that was cover cropped experienced less rainwater runoff after a heavy spring rain. He showed attendees a photo highlighting the difference in water quality between water runoff on a field with cover crops and without cover crops. The water was cleaner and came out slower from a runoff pipe in the field with cover crops compared to the field without cover crops.

Limited tillage has also contributed to no longer needing to clean out his ditches every year, which is a sign of not losing topsoil, he said.

“There are hidden costs of tilling,” Chappell said. “If there were dollar signs in the mud going off the field we’d stop doing it, but there’s not.”

Following soil health principles and keeping soil disturbance to a minimum, Chappell said he only pulls out a tillage tool when it is necessary. For example, he might need to smooth out ruts in fields that were damaged during a wet harvest season.

As an avid fisherman of the White River in northern Arkansas, Chappell noticed how the upper portion of the river was clear while the lower half was not. He recommends cover crops and no-till farming as ways to improve water quality of the lower portion.

“To the rest of the country, we’re causing a dead zone in the Gulf … and we’re losing 24 billion tons of topsoil every year in the farming regions of the U.S.,” Chappell said. “That is a huge amount. It is ending up in the Gulf and the rivers.”

Loss of topsoil also contributes to muddying of the rivers, and flooding, if they are not dredged, he said.

How he does it

Chappell said he plants cereal rye in the fall on fields where he will plant soybeans in the spring and radish where he will plant corn. A disc planter, dropping cover crop seeds under flattened cash crop residue, follows his harvesting combine to save on fuel. In the spring, he terminates the cover crop with glyphosate and plants his cash crop. He said he has not had issues with emergence of his cash crop through the residue in the spring. He also spreads compost and is in the process of integrating poultry and cattle to improve soil health.

“This is cheaper to do than the way we used to,” Chappell said. “It’s $15 to $20 an acre to run this drill, for the seed, the man and fuel and the equipment. That’s it. When you compare that to two tillage passes to incorporate all the corn residue, and then pull your beds up and lay down some residual herbicide, we’re at 25 percent or less at what it cost for the normal operation. So, we’re saving money and we’re doing fine.”

What to know about cover crops

The proper use of cover crops can produce several benefits for production systems in Arkansas including improved soil health, increased nitrogen, and additional weed control options, according to research done by the Arkansas Agricultural Experiment Station.

Cover crops can also provide biomass to increase soil coverage and soil organic matter, as well as aid in nutrient redistribution for the next cash crop, said Trent Roberts, professor of soil fertility and soil testing and interim head of the crop, soil and environmental sciences department.

Since some cover crops go better with certain cash crops, having a plan for the next cash crop and goals of the cover crop are important, Roberts said. ∆

JOHN LOVETT: University of Arkansas