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The forage value of cover crops

Western research shows cover crops can be worth their weight for grazing or even baling

Extended drought has forced many farmers across Eastern Canada to seek alternate feed sources for the coming winter. It’s even got some producers thinking about the cover crops on their farm and on neighbouring farms.

The growing popularity of cover crops among grain farmers may have come at just the right time for cattle farmers who are sitting around their kitchen tables this fall, discussing culling options.

It isn’t all roses. Without knowing just what the feed value might be that’s locked in those covers, many livestock producers may not want to risk introducing their herd to such novel feedstuffs. Similarly, many crop producers are equally hesitant to disturb the soil rehabilitation process, which is why they planted the covers in the first place, and many of these farmers have neither the equipment nor the forage-harvesting experience to bring these blended crops to market.

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But the popularity of grazing cover crops in Western Canada may offer solutions to both groups of farmers in the East. Although it’s far from a common practice, there is a buzz about grazing cover crops both for the improvement of your soils and as a means to reduce winter feeding costs.

Some researchers have been hearing anecdotes and chasing scientific evidence for a year or more. For instance, Nora Paulovich of the North Peace Applied Research Association in Alberta says it’s been about three or four years for her.

Paulovich says that for years, farmers have been operating under the assumption that if you’re planting more than one crop, some plants will naturally rob the nutrients and moisture that the other crop needs from the soil. But what she’s seen in her crop garden is that this really doesn’t seem to be true, and there are actually beneficial relationships between many species which give rise to improved performance on all accounts, particularly in extreme weather conditions.

“We had an extremely dry year last year, nothing grew well, and we had lots of grasshoppers,” Paulovich offers as an example, “but some of our producers had cover crop mixes that did do very well. One fellow had a diverse mix he seeded the same day right next to a monoculture triticale. The triticale looked horrible, grasshoppers moved in and ate most of it, but the cocktail mix right adjacent was amazing.”

Limiting grazing is recommended until you get a good feel for forage quality.

Limiting grazing is recommended until you get a good feel for forage quality.
photo: Sandy Black

Cocktail blends seem to kick-start soil microbes, which then dine and take up more nutrients more efficiently than in monocultures, Paulovich says. No one blend is clearly triumphing over others as far as she can tell, and everyone is still experimenting to find what they like best, but Paulovich says they do find that aiming to include a cool-season grass species, a cool-season broadleaf, a warm-season grass, and a warm-season broadleaf is a good place to start.

“The ryegrasses are fantastic,” Paulovich says as she starts to tick through a mental list of species they’ve worked with. “I’m not a huge fan of sorghumgrass. Crimson clover is doing well, the hairy vetch is absolutely awesome, and the cows really do like millet. Our brassicas and kale are doing well. Buckwheat turned out to be an awesome crop this year. We are thinking about maybe cutting back the spring oats seeding rate; it is taking over a bit.”

This year they seeded between 30 and 40 pounds per acre of oats in their blend and she figures they’ll cut that back to five or 10 pounds per acre after watching it canopy over other young seedlings way too soon in the growing season. She says they also put 20 to 25 pounds of forage peas in with that, as well as other species of brassicas which she recommends keeping below one pound per acre. Other species added to her trials this year include hairy vetch, millet, sunflower, kale, sorghum-sudan, bursting clover, crimson clover, italian rye, tillage radish and grazing turnips.

Learning all she can at work helps with the learning curve at home, where Paulovich raises cattle with her husband and kids.

“It’s fun to go out there and see what the cows go for first,” she says. Last year was very dry, so she admits they let the cows take the pasture down more than she would have liked at first. “If you have a good year, mob graze so that they leave quite a bit behind and tramp that into the ground,” she suggests.

Building organic matter

Over in Rivers, Man., another farmer doing a lot of his own grazing research is Clayton Robins. Unlike Paulovich, Robins is very focused on studying the impact of very specific plant species on cattle nutrition so he’s grazing his commercial herd on tetraploid italian ryegrass, aurora festuloliumn (a hybrid between ryegrass and fescue), chicory and plantain.

Clayton Robins

Clayton Robins
photo: Sandy Black

If his soils weren’t so saline, he says, he would grow red clover too but instead he’s getting better results from sweet clover, yellow blossom, and hairy vetch. “We also tried some brassicas this year, some of the hybrid brassicas out of New Zealand and were very disappointed in them,” Robins says. “There is a lot of canola, so fleabeetles are naturally very high and few plants survived.”

In designing his blend, Robins targets at least 50 per cent grass in his final stands. That’s hard to achieve, he admits, but it offers the highest level of sugar to the cattle and he says it’s a slow-release energy that rivals green barley. Going into all that lush pasture, it’s important to manage intake moisture by providing a dry feed source, a very good-quality hay or straw. “One of the things I learned early on is the tipping point seems to be 17 or 18 per cent dry matter in a growing plant,” he explains. “Once you’re below that, you’re going to run into digestive upsets and intake issues.”

Like so many farmers, Robins seeds his forages under oats and fababeans. “Then we put it up as a round bale and we leave the bales in the field,” he says. It’s a time-savings advantage, bringing the cattle back to graze the same fields later. “We strip graze, just take the plastic off as we reach those bales, and provide two bales a day for a herd of 35 cows.”

In addition to producing a highly digestible feed, Robins says he’s found that another advantage of focusing specifically on high-sugar-producing plants for feed is that these plants also produce a lot of sugar in the roots to drive soil biology. As a result, he’s building organic matter extremely fast in his soil and he also says he’s seen huge improvements in water infiltration this year, compared to four or five years before he got started with these cover crops. “Places in the field where water would normally lay, where we couldn’t have walked let alone get a tractor by, we took the main crop off and the surface of the soil wasn’t even sticky.”

On Robins’ farm, good forage-producing cover crops also seem to be the best choices for improving organic matter and overall soil quality.

On Robins’ farm, good forage-producing cover crops also seem to be the best choices for improving organic matter and overall soil quality.
photo: Sandy Black

A second look

Meanwhile, Dr. Bart Lardner, a professor at the University of Saskatchewan and active researcher with the Western Beef Development Centre, offers some sober thought.

“If we’re improving soil this much, yes, I totally agree we need to do rotational cropping to improve organic matter and retain nitrogen, it’s a good thing,” Lardner says, “but let’s huddle down and do some research.”

Lardner isn’t contesting any of the work completed by Paulovich or Robins, but he says there are individuals in the industry who make claims he’d like to put to the test next year. There isn’t any silver bullet that’s going to work for everyone, he believes. In times of drought, farmers’ backs are particularly up against a wall and he sympathizes. “You, as a producer, have to look at all these different options and then figure out which one will work in your environment.” Use your common sense, he urges.

Before you ever start feeding, take samples pre-graze. Remember though that the sample is a subsample for your whole field, and if your results seem suspiciously high or low, test twice. Look for the protein score, fibre levels, energy, ADF and NDF, and then check with specialists to make sure you can balance the nutritive value of those forages according to the needs of your animals.

Lardner says research on grazing alternatives seems cyclical in popularity. “About 15 years ago, turnip was all the rage,” he recalls.

The Western Beef Development Centre has several fact sheets as a result, many of which take feed costs into account. Some of these novel seeds may be high priced, so these valuations of some of the more conventional grazing options could be worth taking into consideration, he says.

Lastly, Lardner advises producers to monitor and manage for nitrates, just as they usually would during any ‘shock environment.’ “I’ve grazed one per cent nitrate cautiously, without any negative issues in terms of animal issues in the past,” he says, but he also notes that gestating animals are not the same as young stock, which would be different again from dry cows.

“Don’t treat it like you put your cows out for summer pasture,” Lardner says. “You have a new system out there. Limit graze and move the wire every four days.”

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Amy Petherick

Amy Petherick is a Contributing Editor for Country Guide.

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