Grazing cover crop trials yield mixed results

SASKATOON — Early results from a cover crop grazing study show mixed outcomes.

The first year of the study, which looked into directly grazing a cover crop at three Saskatchewan and one Manitoba site, showed the effects of weather and that cattle may have some grazing preferences, according to the researcher and participating producers.

Jillian Bainard from the federal research centre in Swift Current, led the project, which collected data from sites at Swift Current, Outlook and Kelliher in Saskatchewan, and near Brandon.

Typically, cover crops are grown to benefit the soil or ecosystem and are plowed down. But Bainard wanted to examine the potential benefits of grazing a forage cover crop within an annual cropping system.

“In a forage system, we’re looking at can we take some of that plant material and get an actual tangible economic benefit as feed for cattle,” she told the Saskatchewan Beef Industry Conference.

The project was designed with a control annual crop, a simple mixture and a complex mixture.

“This past year, we had peas. This coming year, we’ll have barley and then we’ll probably go to an oilseed,” Bainard said, referring to the control trial.

The simple mix was oats and peas; the complex mix contained eight different crops: oats, barley, peas, hairy vetch, tillage radish, Winfred brassica (a hybrid forage brassica), millet and phacelia.

“We came up with a list of species that we were all reasonably comfortable with trying and that you can easily obtain seed for,” she said. “That can be a challenge.”

In the first year of the trial, the weather proved to be the biggest challenge.

At Swift Current, in the brown soil zone and semi-arid conditions, the trial was seeded May 29 in extremely dry conditions.

Bainard said typically mixtures are seeded slightly later to push available forage to a little later in the summer.

The Swift Current site used 1.5-acre paddocks initially, with eight yearlings in each paddock, and then rotated through.

On Aug. 1, the yearlings went into the simple mix, which had come up and looked reasonable with some rains. Dry matter production was just more than 5,000 pounds per acre at that time.

Bainard said the steers “blew through” the forage quickly and after six days of grazing they were moved. This translated into 28 days per acre per animal.

“We were all really surprised. We wanted them to stay out a lot longer but they were actually losing weight, about two pounds a day,” she said.

Although the forage looked lush and green as it dried down, it went quickly, she said.

When the animals went into the complex mix Aug. 6 they ate everything except any of the brassicas. They were left to try to push them, but the cattle also lost more weight.

As the cattle were moved through different areas on Sept. 18, they came back to the complex mix and began to graze the brassicas.

“We don’t have plant information at this time but what we’re thinking is that palatability does change,” Bainard said.

Or, they might have just become used to eating the brassicas.

“Because of that, we could increase those grazing days,” she said.

One other odd finding was that the steers at this site did not like peas.

The trials near Brandon, at Manitoba Beef and Forage Initiatives, and Outlook didn’t fare well at all.

In Manitoba, a black soil zone with typically high moisture, the crops were seeded June 9 into small paddocks of less than an acre.

“Unfortunately, we had what we’re calling a polycrop failure,” Bainard said. “We ended up mostly with wild oats or weedy millet.”

Unfortunate timing played a role, as rain followed a pre-seed burn-off and the weeds got out of control before the crop could establish. Cattle were still able to graze but researchers weren’t able to answer their specific questions. A new site is expected to be seeded this year.

At Outlook, Sarah Sommerfeld, who works with the provincial agriculture ministry but is also a producer, collaborated on the project. She described her site as dark brown soil with moderate moisture and a high water table.

“This was very much a situation of lessons learned and try again,” she said.

The family seeds about 5,000 acres to grain and forage, under irrigation and has 45 cow-calf pairs.

The two-acre trial site was seeded June 8, after all other seeding was done on the farm, following a pre-seed burn-off of glyphosate and herbicide tank mix on the larger part of the field.

“The intention was to not use the burn-off with the herbicide tank mix on the plot area,” she said.

She was worried about residual effects on the broadleaf crops, but in hindsight said the whole area probably should have been sprayed.

“On July 22, the plot area… is basically entirely foxtail barley,” she said. “Less than ideal conditions resulted in polycrop failure.”

The site had no moisture until late June and combined with the late seeding date and weed pressure it failed, although the rest of the field produced barley greenfeed, she said.

Duane Thompson, at Kelliher, had a different experience. He intensively and rotationally grazes 1,100 cow-calf pairs on almost entirely perennial forage in the black soil zone with typically high moisture.

The site was “a postage stamp corner” of a grain farming neighbour’s wheat field. Thompson said it’s a bit nerve-wracking to fence off 25.5 acres with electric wire and move the entire herd into it; he feared for the neighbour’s crop.

The crops were seeded May 24 and didn’t get rain until June 20, like much of Saskatchewan.

But he said the stand was impressive when it came time to graze.

“They just walked in and disappeared,” Thompson said. “In all honesty, I thought we were going to be moving them out by about 3 o’clock that afternoon.”

But when he drove by all were content and eating.

“One thing that was very evident was how much they preferred the simple mixture over the complex mixture,” he said. “Eighty-five to 90 percent of the herd went over to that area of the plot and grazed it pretty hard right off the bat.”

The cattle remained content as they worked their way into the complex mixture.

Thompson said he was impressed with the 86.6 cow days per acre on the plot. The animals tramped down some crop and left quite a bit of litter.

“As a cowboy you’re always pretty concerned about the animals and how they’re going to handle it because they came off a perennial stand and they went on to this and their manure didn’t change a lot and they were happy so I was happy,” he summed up.

Bainard said although it is just one year of data, weather and conditions will make or break a system like this.

She said producers should recognize there are real risks and challenges and agronomic management is important.

Four trials are planned again this year and the previous sites will be seeded to barley as a feedback crop to see if there were impacts from the mixtures and grazing.

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