Intercropping wheat

Trials done in Ames, Iowa, used winter wheat for harvest and as a cover crop to test the profitability of a relay intercropping system.

The timing can be tricky, but finding ways to get an extra crop out of a field every year may pay off for farmers looking to add some profitability to their operations.

While some farmers use cover crops in the fall and winter seasons to reap agronomic benefits, an option that could work its way into more Midwest fields is relay intercropping, according to Iowa State University Extension crop management specialist Mark Licht.

“How can we get three crops in two years?” Licht said. “Cover crops can be a challenge for (some farmers), but they aren’t getting any profit out of them. There are small grains like winter wheat and cereal rye we can grow in Iowa and get some decent production out of them.”

Licht said the system is “not easy,” but it could work in Midwest fields based on some trials run in a couple Iowa fields during the 2018-19 seasons.

In one Kalona, Iowa, field, the farmer went from corn to cereal rye to double-cropping soybeans. The cereal rye posted yields of 46.1 bushels per acre in 2018 and 30 bushels per acre in 2019. The double-crop soybean yield was 23.2 bushels per acre in 2018, while the beans were not harvestable in 2019.

Licht does note the early frost in 2018 likely affected these numbers.

There were other trials done in Ames using winter wheat for harvest and as a cover crop. Yields for the wheat fields came in around 57.2 bushels per acre in 2018 and 30.1 bushels per acre in 2019. Meanwhile, soybean yields came in at 16.3 and 33.0 bushels per acre in the double-crop system for those two years.

Licht noted there is the possibility of increased production risks for this method, and timing can be a key factor in how well this system works.

“You have to time the soybean planting before the wheat or rye starts jointing,” Licht said. “Once it starts to joint, your wheel tracks are going to lay it down and you’ll have different heights you’ll be trying to harvest. That’s quite critical. The other challenge is harvesting the small grain without doing too much damage to the soybean crop.”

Justin Hartschuh, with Ohio State University Extension, said this is a process utilized in his area. Some of Ohio State Extension’s work with wider wheat rows has been effective in making relay intercropping more successful.

“We’ve done some work with 15-inch wheat and twin-row wheat,” Hartschuh said. “We’ve done some where we planted in late April into the wheat. The wheat hadn’t jointed yet, and in the wider row, the soybeans didn’t get lengthy and lodged as it would in 10-inch wheat. It wasn’t as dark down there and was getting sunlight.”

He said in his coverage areas in Ohio, he’s seen farmers bringing in wheat yields at nearly 70 bushels per acre and soybean crops that come in at 50 to 60 bushels per acre.

Hartschuh said beginners will need to start by looking at how they want their soybeans to look in the field and work with the wheat crop from there.

“The first key to getting started is figuring how you want to plant the soybeans,” he said. “Then you figure out row spacing and what kind of tire width spacing you’ll need to line everything up.”

For those looking to get into the process, Hartschuh said taller wheat varieties may bring more benefit, and the system favors more of a bush-like soybean variety. That allows for easier wheat harvest without damaging as much of the soybean crop.

One savings Licht saw in his trials was not needing any preplant herbicides as the wheat crop took care of weed issues they would have going into the soybean plantings.

“Essentially, we had a post-application herbicide we still needed and something with residual control to help with the late flushes of waterhemp,” Licht said. “It was a really neat system to watch.”