This story also appears in our University of Missouri College of Agriculture, Food and Natural Resources’ Agricultural Research Center Magazine. Stop by your local Research Center to pick up a copy!
With a focus on sustainable agriculture, the University of Missouri College of Agriculture, Food and Natural Resources’ Hundley-Whaley Research Center has looked at numerous ways to maintain that important ecological balance.
Hundley-Whaley, located in Albany, has been using cover crops during the past few years as part of that focus. Cover crops can be used to manage a variety of issues, including soil erosion, soil fertility, soil quality, water, weeds, pests, diseases and wildlife.
“With the research that we’ve done, we’ve seen the numerous benefits that cover crops can provide,” said Superintendent Bruce Burdick. “Along with improving water quality and soil structure, we’re seeing a reduction of fertilizer loss and erosion when we incorporate cover crops into a field.”
Finding the correct cover crop depends on a host of factors and is normally specific to the farm. Landowners need to identify their goals when it comes to selecting the correct cover crop. Finding out how the cover crop fits into the rotation is key. Summer and winter cover crops accomplish different objectives, so deciding what is most important is part of the process.
There are a number of cover crops to choose from, too. Burdick said they have used cereal rye, radish and crimson clover in their research.
“Rye is probably the most forgiving and easiest to grow,” he said. “It’s hardy. Plus, when we plant rye into the late part of the season, you’ll generally get growth the next year. Rye is relatively inexpensive as well and has a massive root system. That root system leads to it having fantastic erosion control potential.”
Hundley-Whaley’s first cover crop trial looked at the yields of corn and soybeans. Each plot was tested with innovative planting systems across different tillage systems, including strip till, no-till and reduced tillage. The planting treatments for the cover crops were done by using broadcast seeding or row cropping with precision planting techniques.
“We saw that they helped us more on the corn side,” Burdick said. “The rye that we used showed the ability to provide proper cover and erosion control. The way we planted it was very acceptable and allowed seed preparation. There wasn’t an excessive amount of residue, either.”
Hundley-Whaley has seen a seven to eight bushel increase per acre in corn and around a two bushel increase per acre in soybeans during their cover crop trials.
Burdick said using rye as a cover crop within a corn field has led to competition problems at times. The two compete for nutrients, leading to issues within the system.
“Rye gives off a chemical that could inhibit corn,” Burdick said. “We’ve started to look at terminating the rye at different timings so we can reduce that competition or tie up. To do that, we’ve looked at different fertilizers to offset what has been tied up. We want to have the benefit of the rye and make sure we don’t have a yield loss in the corn.”
That termination timing project has been another focus at Hundley-Whaley. The Center has looked at the moisture removal by the cover crop at various termination timings. They terminated the cover crop at six, 12, 18 and 24 inches, and rolled it to mash it down once it went into the reproductive side.
“It kind of goes against the grain of the common thought pattern of we have to let residue sit there as long as we can,” Burdick said. “We saw the best yields when we removed the residue, as a competitor, earlier into the season. Our highest yields came when the cover crops were terminated at 12 to 15 inches. Once we let them grow past that, we saw some yield loss.”
The key to a cover crop system is giving it time to take hold.
“It’s definitely not a one-year thing,” Burdick said. “You can’t expect perfect results right away.
“It really depends on which cover crop you use and the timing. Part of what we’re working on is if we could go in earlier and plant cover crops earlier in the season to get more fall growth. The challenge with that is that with corn and soybeans, most landowners want to wait until the end of harvest to plant anything else. While that does work well, we are trying to see how planting the crop earlier can affect the system.”
Hundley-Whaley saw its best stands when the seed was planted into the ground instead of with high-clearance sprayers or aerial applicators.
“Those two seed planting methods have been hit or miss with us,” Burdick said. “There’s not quite the precision there. We’ve seen much better results when we put it straight into the ground instead of just throwing it on top of the soil.”
The Hundley-Whaley Research continues to ramp up its projects related to cover crops as well. They are working with the Missouri Soybean Association on the influence of cover crops on nematode populations. The Center is also looking at different varieties on those populations.
“Our goal is focused on retaining nutrients and not putting them in the water downstream,” Burdick said. “Those nutrients are key to the yields that we want. We also don’t want to have an influence on negative water quality downstream.”