Are cover crops worth the cost?

When Brad Zimmerman decided to try growing cover crops 10 years ago, the Groveland, Illinois, corn and soybean farmer had a list of worries: “I was concerned about the cost, the time it would require, the possibility that the cover crop wasn’t going to grow, and the possible yield drag on my cash crops,” he says.

But Zimmerman reasoned that cover crops could improve the soil biology. This could improve his cropping system’s efficiency, thus reducing synthetic fertilizer inputs over the long term.

He took the plunge and hasn’t looked back. He added cover crops on a small scale, learned from his mistakes, and took advantage of cost sharing through USDA’s Natural Resources Conservation Service (NRCS).

The long-term benefits to his cropping system have been well worth the effort. Soil organic matter has improved along with other soil health improvements, resulting in cost savings due to reduced applications of synthetic fertilizers.

Yet while the benefits of growing cover crops are evident to Zimmerman, the practice continues to meet resistance from many farmers, according to Rob Myers, director of the University of Missouri’s Center for Regenerative Agriculture.

Concerns about cost are among farmers’ top four reasons for not growing cover crops, says Myers, who also serves as regional director of Extension programs for the USDA North Central Region Sustainable Agriculture Research and Education (SARE) program. Surveys conducted by SARE look at cover crop adoption rates and farmers’ experiences with cover crops. This data combined with his own research has led Myers to write extensively about the practice.

His recent book, “Cover Crops: Improving Life on the Land,” provides a resource for beginning cover crop growers. 

Another of Myers’ works is the SARE report Cover Crop Economics. Drawing data from farmer surveys, the report estimates that seed costs for cover crops can vary from $10 to $50 an acre. The seeding of the cover crop can cost $5 to $18 an acre, and termination expenses can amount to as much as $10 an acre. The total median cost is $37 an acre.

In the absence of cost-sharing incentives from off-farm sources, the initial investment may yield no immediate payoff. “In the first one or two years, you may see a reduction in net profit,” Myers says. “But on the third year, you may start to break even as a result of better soil health, leading to higher cash crop yields. By the fifth year, you may start to see a positive net profit because of gradually increasing yield benefits generated by cover crops combined with reduced applications of fertilizer or herbicide, or reduced need for tillage.”

Have a goal in mind

Cover crops’ benefits to the soil system and net profitability accrue most rapidly when pairing cover crops with no-till, Myers notes.

Myers’ SARE report includes multiyear cover crop budgets for corn and soybeans under various management scenarios.

Setting a goal for what you want cover crops to accomplish can be a way to see positive results more rapidly. “From the beginning, have a goal in mind when you begin planning how to add cover crops to your system,” says Stephanie McLain, state soil health specialist for the Minnesota NRCS. “Many farmers begin by trying to figure out how to control erosion. Or their goal might be suppressing weeds, improving water infiltration, or improving soil health or soil function in general,” she adds.

More yield, fewer inputs

Zimmerman’s goal of planting cover crops to improve soil biology has led to significant savings, resulting from increases in soil organic matter. “In a six-year period between soil tests, we’ve increased soil organic matter from 2.7% to 3.3%,” he says. “A higher level of organic matter is the reason our soil is more productive. The soil is able to release more nutrients and retains water better, so that the plants are better able to withstand dry periods. We can raise crops with reduced inputs.”

In 2023, Zimmerman’s corn yielded 255 bushels per acre after receiving just 150 pounds of synthetic fertilizer. “As a result of natural fertility in the soil,” he says, “we saved the cost of applying an additional 100 pounds of N, which might normally be required to achieve such a yield.”

Zimmerman’s experience indicates that improving soil health pays off economically. The Soil Health Institute quantified the economic benefits in a survey of 100 farmers in nine states who had implemented soil health-building practices, such as no-till, reduced tillage, or growing cover crops, for at least five years. According to an article published in Successful Farming in April 2023, the results showed that the surveyed growers increased net farm income by an average $52 an acre for corn and $45 an acre for soybeans.

This increase in net profitability resulting from improved soil health is most likely to manifest itself as a reduced need for inputs rather than yield increases, Zimmerman notes.

“The cover crops feed the soil biology, and that makes the soils more efficient at releasing the nutrients that are already stored there and making them more available to plants,” he says. “As a result of that process, we save money because we’re reducing the synthetic nutrients we’re applying.”