Jason Mauck might be the social media darling for the concept of keeping a constant canopy in crop fields all growing season. The Indiana farmer accomplishes this through relay cropping.
“I don’t have anything against cover crops by themselves,” Mauck explains during the Farm Progress Virtual Experience soil health panel, “but if we can cohabitate and get some revenue off our cereal grains, then it makes the economics work a little bit better for us.”
Mauck was only one presenter in a panel discussion about the use of cropping systems and cover crops to improve soil health.
Keeping soil, plants cool
Mauck’s journey started five years ago with a change in cropping system. He ventured into intercropping wheat and soybeans. “It took about two to three years of mistakes to really figure out the relationship of how we can turn it from two competing crops into two crops that kind of help each other out," he says.
Today, he intercrops corn and soybeans, along with wheat and cover crops.
Mauck relied on research from Hawaii to develop his system. A plant breeder figured out what most farmers realize — that plants stress out in the afternoon. So, the goal is to keep both the soil and plant cool during hot summer days in the Midwest. And this is where the canopy comes in.
HARVEST TIPS: Harvesting intercrop fields takes adjustments to the combine header. However, Indiana farmer Jason Mauck says it has worked well over the past three years.
On his farm outside of Gaston, Ind., Mauck planted 4,000 corn plants on 60-inch rows with soybeans planted in between. With this method, corn plants are putting on three to five ears. He contends it is because the plants can capture light on all of their leaves.
As the sun changes position during the day, it casts a shadow on the soybeans. Throughout the day, the soybeans will see direct and indirect light. Mauck says his beans simply grow better.
But he does not stop there. “I’m integrating livestock with cover crops to produce multiple crops and get more value out of the 365 days that we have in the year and all four seasons," he says.
Focus on nutrients
Nebraska farmer Dan Gillespie changed cropping system to include planting green with the use of cover crops. He too travels around the state as a no-till specialist with the Natural Resources Conservation Service based in Norfolk, Neb., sharing his on-farm experiences.
“The purpose of the cover crop is to shelter or protect the surface of the soil until we get crop canopy,” Gillespie explains. “At which point, in the dark and moist understory, that cover crop lays down on the soil surface and all of a sudden we're cycling nutrients.”
Gillespie uses cereal rye as a main cover crop. Last year, he grew non-GMO soybeans and planted them green into the rye cover.
For a long time in the field, he admits it looked like he was growing a rye crop. “I like the way the rye sequesters all the nitrites and makes the soybeans go to work,” he says. However, the rye took a little longer to die off.
COVER OUT WEST: Nebraska farmer Dan Gillespie found that cereal rye and soybeans make a great mix. The practice sequesters nutrients while providing enough for the soybeans.
Gillespie was concerned that perhaps he sequestered too many nutrients in the cover crop, so he ran a biomass assay. There were 3,300 pounds of carbon per acre, 120 pounds of nitrogen, 55 pounds of phosphorus, 120 pounds of potassium and 12 pounds of sulfur.
“That’s enough to grow my next corn crop right there,” he notes. Which raised another concern, did he short his soybeans on nutrients?
He took leaf tissue samples. “They all showed up perfect, well in range,” Gillespie says. “So that tells me you can grow these two crops together.”
And Gillespie says the biggest boost he sees to using cover crops is the boost it offers in terms of organic matter.
Gillespie has tested fields ever since he began farming. His organic matter went from 2.1% to 3.8% in just 20 years.
“But I think the majority of that improvement has happened since I started doing continuous cover crops,” Gillespie adds. He started planting cover crops on his farm in 2012.
Centuries of loss
“On most of our U.S. soils, on average, we’ve depleted about half of the soil organic matter through tillage over time,” says Rob Myers, an adjunct associate professor in plant sciences at the University of Missouri and the regional director of Extension programs for NCR-SARE. He says today on many farms, soil looks more like bricks, but it should look and function as a sponge.
“One way to think about it is by the bulk density of the soil,” Myers explains. “If we have high bulk density in our soil, that's roughly equivalent to a brick, not much porosity there, whereas the sponge would be equivalent to lower bulk density. As we get more soil organic matter, we move toward lower bulk density. And, of course, that helps us take up water.”
Myers says a sponge-type soil, with its holes, allows for more water-holding capacity and infiltration. “We're also feeding those soil microbes, having better supply of crop nutrients and improving the rooting.”
He adds that with a lot of soils, farmers have lost half of that sponge capacity. “And that's what we're trying to do in rebuilding our soil health.”
Myers says the good news is through practices such as Mauck’s constant canopy and Gillespie’s use of cover crops, there is a way to build back organic matter. It shows that these systems can improve soil health on farms across the country.
To watch this breakout session or others, visit the Farm Progress Virtual Experience at FPVExp.com. The show is free and open through summer 2021.