Research Highlights

Cover Crops, Grazing and Soybeans Can Be a Complicated but Workable System

By Carol Brown

The word “system” is crucial in farming. Farmers have systems for everything from daily tasks to what’s grown on their land and when. Raising livestock certainly adds complexity to the agricultural system.

Miranda Meehan, North Dakota State University associate professor, is leading a research project that caters to those farmers who grow crops and raise livestock. An expert in livestock environmental stewardship, Meehan is exploring if grazing cover crops and soybean production fit well within both the cropping and grazing systems. The project is supported by the North Dakota Soybean Council. 

“We want to find out how this research can benefit both farmers and ranchers,” says Meehan. “I was getting questions from livestock producers on how fall grazing might impact the cover crop stand in the spring. They were using winter rye as a cover crop and as a forage.”

Meehan’s research entails a winter rye cover crop, also known as cereal rye, that is dual-grazed in both fall and spring, grazed only in the spring, non-grazed rye, and no cover crop, at two locations in the state. The team terminated the spring cover crop, then planted soybeans immediately following termination and measured soybean yield at harvest. All sites were under no-till management. 

“In terms of soybean production, there were no differences between any of the treatments at harvest,” she explains. “We had some dry periods during the summer and we believe the cover crop biomass helped retain water in the field. Even though the soybeans in the winter rye were delayed in their development, they were able to catch up to the plants that got an earlier start in the spring without the rye cover.”

When producers grow cash crops, use a cover crop, and have their livestock graze that cover crop, the system gets complicated. Meehan is examining each of these components so that producers can get optimum performance from all areas.

Cattle Performance

“We compared the dual grazing treatments with spring-only grazing and no grazing,” Meehan says. “Even though we had a dry fall, there was enough cover crop established for the cattle to graze for one week. We had nine head on each site in the fall and 15 head per treatment at each site in the spring, which was grazed for two weeks.”

The team examined how the cattle fared with grazing winter rye. They measured their weight gain or loss after grazing on all the treatments. 

“With this experiment, the cattle were comparable to what we would expect in a grazing scenario at their stage of development. The cover crop was meeting their nutritional needs,” she says. “Granted, they didn’t perform as well as cattle that were in a dry lot and getting a high-energy ration. But they still had good-quality forage for their nutritional demands. We also didn’t see any differences between the dual-grazed cattle and the spring-grazed cattle.”

Cover Crop Performance

The team measured cover crop biomass before grazing in the fall and spring. This helped them determine how many cattle and how long they could graze on the sites. They also measured the winter rye to see how much forage the cattle consumed. Additionally, the team measured ground cover in the no-till plots, which included residue from the previous crop, weed presence as well as the live cover crop. They compared this data to a rye plot that was not grazed and a bare ground check plot. They found the grazed winter rye provided similar ground cover and weed suppression as the non-grazed winter rye.

“We saw that fall grazing did not impact winter rye forage production in the following spring. We also saw no impact on the soil properties, which is good, as there is concern about soil compaction when animals are in the fields,” Meehan comments. “We didn’t see any difference in terms of nutrient properties either, which can be affected with manure and urine coming into the field. But these types of changes can take time to emerge.”

Meehan is in the beginning of the second year of this research. She is hoping to have the project funded for a third year to be able to see these differences when implementing the practices. The rye cover crop was planted this past fall, and next spring the team will plant corn for silage. She plans to go back to soybeans after that. 

After one full growing and grazing cycle, Meehan believes cattle can graze in the fall without harming spring cover crop establishment. Integrating livestock and a cover crop can be a good opportunity for an additional return-on-investment in cover crops, she says. 

“There are economic benefits to grazing cover crops,” says Meehan. “Farmers can save fuel costs by not hauling feed out to cattle. And if pastures aren’t ready to graze, winter rye can fill a niche within the livestock production system by providing a low-cost supplemental forage. If farmers are already investing in a cover crop for soil health purposes and to prevent soil erosion, why not get an extra benefit of forage for their livestock, too?”

Published: Mar 4, 2024

The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.