Precision Conservation Management recently conducted a case study identifying the most profitable cover crop fields in Illinois and how those fields were managed.

PCM was created in response to the Illinois Nutrient Loss Reduction Strategy goal of reducing nitrogen and phosphorus losses by 2035.

“Anyone who is active in the area of ​​water quality and environmental issues knows that the conversation is changing,” says Laura Gentry, director of water quality science for the Illinois Corn Growers Association. “The tides of public opinion are changing and changing.”

After the NLRS Biennial Report proven that no progress has been made toward nitrogen and phosphorus loss goals, Gentry says mandatory conservation practices could be on the horizon.

“We believe the biggest gains toward NLRS can be seen in managing nitrogen and phosphorus through tillage and cover crops,” he says.

Best Practices for Cover Crops

Gary Schnitkey, an agricultural economist at the University of Illinois, studied the most profitable farms using cover crops. He found that the number one cover crop species used in a corn-to-soybean rotation is cereal rye. This is due to the low cost of cereal rye, its ease of establishment and its ability to overwinter.

Cereal rye is usually planted after the corn harvest, but the planting method varies. Each method has pros and cons:

Broadcast with dry fertilizer. Low cost establishment but worse.

The transmission followed with a light tillage pass. Moderate costs but better establishment.

Drilled or planted. High costs but good establishment; requires more labor and time.

Attachments to combine. It eliminates the tillage step and generally has lower costs, but it slows down and complicates harvesting.

The consensus in Illinois is to plant soybeans in early April to increase yield. Terminating cover crops before planting reduces the risk of competing with soybeans, but decreases the chance of eliminating herbicide passes. Terminating after planting increases the risk of competition with soybeans, but increases the chances of eliminating herbicide passes.

Schnitkey says some of his summary findings on planting a cover crop before soybeans are:

Using cover crops in a soybean-to-corn rotation is more challenging because corn is less tolerant of stress and cover crops sequester the nitrogen needed to grow corn. The timing of planting and finishing is also more difficult, and costs are harder to control.

Schnitkey says the three systems that show the most promise for a soybean-to-corn rotation are clover, cereal rye and terminal cover crops:

Clovers. So that the seed is effectively established by aerial seeding before the soybean harvest in late September.

Advantage: Clovers sequester nitrogen, which can then be available to corn.

Disadvantage: seeds and planting methods are more expensive.

Cereal rye. Plant after soybean harvest using low seeding rates and finish early before corn planting.

Advantage: Costs are lower.

Disadvantage: Reliance on cereal rye raises concerns with successive planting of grasses.

Terminal cover crops, such as oats or turnips. Plant in the fall after soybean harvest and end frost.

Advantage: No special finishing is needed in spring.

Disadvantage: Lack of spring growth of the cover crop means no weed control or nitrate sequestration.

Overall, Schnitkey found no increases in yields or increased returns for operators with the use of cover crops.

“If you’re new to cover crops, we suggest planting them before soybeans and spreading fertilizer on top of your cereal rye,” Schnitkey says. “Plant soybeans in early spring, finishing the cover crop before planting.”

Schnitkey and Gentry recommend using financial incentive programs to cover any additional expenses associated with planting cover crops.

Incentive programs

The PCM program and specialists work with farmers to collect field information for a customized report that outlines financial and environmental opportunities.

Gentry says several federal, private and combination programs can provide financial incentives for cover crop implementation, such as:

“Work with a PCM specialist to understand which of these programs stack up and which don’t,” Gentry says. “There are incentives for growing cover crops, for no-till and strip-till, and for nitrogen reduction.”

For more, visit precisionconservation.org.