Why graze cattle on cover crops?

When no-till farmer Ben Cramer of Healy, Kansas, began adding cover crops to his crop rotation of winter wheat, grain sorghum (milo), and fallow, it made sense to him to graze the cover crops with livestock.

“We’d always had a cow herd and grazed the milo after harvest, and the stalks from the corn we sometimes included in the rotation,” he says. “With all the research out there, we also knew that cattle add a lot of soil biology to the cropping system.”

With the grazing of cover crops expanding his opportunities to improve soil health, Cramer has seen levels of soil organic matter nearly double in the past decade. To boot, the economic returns from the grazing pay for the cost of growing the cover crops.

Because conserving moisture is one of his goals, Cramer retains a fallow period in his production system after growing a crop of winter wheat. He plants the wheat in fall, harvesting it in late June or early July of the next growing season. He plants no cover crop after the wheat and controls weeds with herbicide.

The spring following the fallow period he plants milo.

“We harvest that in fall, and after that we may grow another year of corn or milo,” he says. “The following spring we’ll plant a warm-season cover crop including species like buckwheat, cowpeas, forage sorghum, German millet, and sunflowers.”

Cramer starts grazing the cover crop in June. “If we’re aiming to plant wheat after the cover crop, we like to get the livestock off by the middle of August so that we can plant the wheat,” he says. “But sometimes we’ll graze the cover crop through winter.”

Increasingly, Cramer has found that the grazing of livestock on cover crops and even cash crops “gives us a lot of options,” he says. “In a dry year when the crops are poor or when grain prices are low, we can graze livestock on some fields. Or when grain prices are high, we can graze less.”

Custom grazing either stocker cattle or sheep lets Cramer take full advantage of flexible options. “Stockers give me a lot of flexibility because they’re easy to move in and move out,” he says.

Building Soil Health

Aiming to take best advantage of livestock grazing as a way to build soil health as well as add value to crops, Cramer has fenced, cross fenced, and piped water across all the cropland he owns. He has also further developed fencing and water systems on his farm’s rangeland.

Cramer put up three-wire, high-tensile boundary fencing and some single-wire, high-tensile interior cross fencing on the cropland in 2017. He also installed shallow lines for water installations for livestock. The cost for both fencing and water development came to about $100 an acre, which he covered himself.

Over time, custom grazing has repaid the investment. The grazing period for a year typically generates $60 an acre on the grazed land.

“If we’re custom grazing stocker cattle, we calculate what to charge by first estimating the amount of forage that’s in a field,” he says. “If there’s 2 ton per acre of forage, we’ll plan to take off 1,600 pounds per acre by grazing, or a little less than half.” He leaves the remaining residue on the surface for ground cover and for the soil microorganisms to recycle.

He decides the stocking rate by estimating that yearlings may eat about 3.5% of their bodyweight per day. One yearling grazing for one day comprises a grazing day. He charges $1 for each grazing day. “We get 60 grazing days per acre for the season,” he says. A two-month grazing period is typical for Cramer’s cover crops.

The income covers the cost of the cover crop seed and the expenses for planting the cover crop and terminating it before planting wheat.

But the measurable economic benefits of grazing the cover crops don’t reveal the hidden value of increasing organic matter in the soil. Results of Cramer’s soil tests suggest combining cover crops with grazing has accelerated the rate at which levels of soil organic matter are increasing.

“When we started no-till in 2006, our soil organic matter was 1.6% to 1.8%,” says Cramer. “When we started growing and grazing cover crops in 2012, organic matter levels had increased to 2.3% to 2.5%. But now, even though we don’t graze every acre every year, the levels of organic matter in the soil have climbed to 3.5% to 4%. The organic matter is increasing at a faster rate than it was earlier.”

Increases in soil carbon naturally go hand in hand with increases in soil organic matter. Whether or not Cramer is able to capitalize on these increases in a carbon market depends on future market development.

“We’ve just gotten started looking at carbon markets, but the programs I’ve seen so far aren’t paying enough,” he says. “I hope we can monetize the carbon in the future if we can find good ways to measure it.”

Sampling for soil carbon at the start of his adoption of no-till, cover crops, and grazing would have provided a baseline for valuing later increases in soil carbon on the cropland, he says.

Learning from the past, Cramer hopes to get a measurement of carbon on rangeland. Because he has just started practicing high-stocking-density grazing on the rangeland, he believes getting a baseline measurement of carbon could be helpful in marketing credits from future carbon increases potentially resulting from the new grazing practice.

While increases in soil organic matter on cropland have been a benefit of livestock grazing, one pitfall has been some compaction on his heavy loam soils.

“To try to mitigate compaction, last fall we planted rye,” he says. “We’re hoping the roots of the rye will help to break up the compaction.”

In the fall of 2022, Cramer took a break from grazing cattle and stocked his fields slated for grazing with dry ewes. He owns the sheep in partnership with another producer.

In the future, he may graze both sheep and stocker cattle in a staggered sequence. “We might start out grazing a field with stockers and follow the cattle with sheep,” he says. “Because of their differences in plant preferences, multispecies grazers would be more efficient at harvesting a multispecies cover crop.”

Creative Ways to Share Labor

When cover crops are green, Cramer likes to move cattle every day, requiring the moving of step-in posts and polywire. He hires the work done on a contract basis. “We pay a per-head per-day fee for the cattle to be moved daily,” he says.

The labor of moving the sheep is provided by the co-owner, who also pays Cramer a share of the forage costs.

Learn More

Email Ben Cramer at bac290@yahoo.com.