Planting summer annual crops for fall and winter pasture

Regrowth of a relay crop after the barley silage was removed in late July.

Extending the grazing season can reduce production costs for cattle. Annual crops can fill in some gaps, or improve soil health before replanting a permanent pasture or seeding another crop.

“A good perennial stand is the most cost-effective forage, and a good long-term investment, but annuals can be a good interim plan,” says Graeme Finn of Southern Cross Livestock, near Crossfield, Alta.

If a pasture or a hayfield needs to be reseeded, using annuals for a year or two can create a better transition while providing good forage for cattle, he says.

Another option on irrigated land is inter-seeding a forage species with a silage crop on irrigated land, to provide stockpiled forage. Once a producer removes the silage, he can turn on the irrigation so the relay cover crop grows.

“This is a huge advantage, to get more production from expensive irrigation land,” says Finn. “This is a great use for annuals. People can still get the tonnage and quality they need, and it’s generally better forage than straight barley. And they also have stockpiled forage to graze in the fall.”

Some producers run livestock through crop land periodically. They seed a cocktail cover crop in the spring, as soon as frost risk is gone, Finn adds.

“Most of the cover crop blends are designed for cool seasons but some include sorghum or corn or sunflower. Generally you can get these cover crops seeded in early May, just like a silage crop, with the soil moisture that’s there to start with,” Finn says.

If weather permits, these crops can come back multiple times after grazing (although that’s an uncertainty, as some years are too dry). Finn says the trick is to graze it down to eight or 12 inches, then let it recover.

“If you allow cattle to take it clear down to the ground in the summer and lose that solar panel, however, it takes much longer for the plants to recover and you can’t graze it again very soon,” he says.

Warm-season plants don’t do very well when seeded early, while there is still a frost risk, warns Kevin Elmy of Friendly Acres Farm, near Saltcoats, Sask. Elmy consults with and gives presentations for producers on improving pasture production and regenerative agricultural management systems.

“If you plant early, it’s best to get some cool-season plants growing, such as the typical oats, barley, or peas, and sometimes utilizing other species like chicory or plantain,” Elmy adds.

Deciding what to plant and when to plant it

Before seeding, think about the goals for a pasture, Elmy advises. The goals and plan will determine the species needed in an annual or cover crop mix, he says.

“If you are planning to break up an old pasture or a hay stand that is old and tired, this means your carbon-to-nitrogen ratio in that soil is probably out of balance and you need to get more nitrogen into the system,” says Elmy. “If it’s hay or pasture you are going to break up, you want to transition it back into production with a blend that contains a high level of legumes — to add a lot of nitrogen — along with the grasses. The next year, you can cut back on the amount of legumes in that seeding and increase the amount of grasses, and introduce a broadleaf into the mix. By year three, you have a lot more options because your productivity is back again.”

A mix with a high number of legumes can transition old hay stands or pasture back into production. photo: Kevin Elmy

Elmy says he recently met with a Manitoba bison producer who wanted a plan detailing what and when to seed, and when to graze it.

“This producer has some grain land but he wants to go to more livestock — bison, in this instance — and have them grazing as much as possible.”

One principle is that starting a tractor costs more money than letting animals harvest their own feed. With that in mind, Elmy advised the bison producer to seed some cool-season annuals for grazing as early in the spring as possible.

Some forages that were once considered cover crops (used to keep the ground covered, prevent erosion and add soil fertility) are now being planted specifically for grazing.

The best balance in a cover crop is to include a mix of grass, legume and broadleaf plants. Elmy suggests drawing a triangle to visualize this balance, using these three main plant groups.

“A good cover crop contains all three plant types. A great cover crop includes a warm-season grass, cool-season grass, warm-season legume, a cool-season legume, warm-season broadleaf and cool-season broadleaf. Diversity is the key,” says Elmy.

A diverse mix is the best diet for cattle because there is always something green in that mix and it provides what they need. It also feeds soil biology.

Along with the cool-season types such as barley, oats and peas, Elmy likes grasses because they yield the most pounds per acre of forage. Legumes, he says “will be the gas you add to the motor to help the system go,” providing nutrients to livestock and fixing nitrogen in the soil.

“The broadleaf plants like brassicas should be used more sparingly because they are non-mycorrhizal,” Elmy says.

Mycorrhizal fungi form a symbiotic relationship with the plants. The fungi colonize the plant’s root system, increasing water and nutrient absorption, while the plant provides the fungus with carbohydrates formed from photosynthesis. Brassicas are highly resistant to mycorrhizal fungi and don’t normally allow the fungi to colonize it.

“There are also some potential feed problems with brassicas, including the fact that they are too high in protein. You only need a little bit of these in the mix, to add diversity and protein,” says Elmy.

Protein balance is important, and so is sugar. Clayton Robins, a Manitoba producer who studied sugars in forages a few years ago for the Nuffield scholarship, did research that shows that the rumen performs much more efficiently if the sugar to protein ratio in the rumen is at least two to one, says Elmy.

“Robins has actually gotten these levels as high as three to one, using some of the high-sugar forages,” he says. That means adjusting the mix to have fewer brassicas and more grass, and selecting some energy-dense grasses, he adds.

Research is also starting to show that to feed soil biology, plants need to be actively growing, Elmy says. Cool-season grasses and broadleaf legumes are best early in the year, but as nights grow warmer in the summer, producers can transition into the warm-season species.

“Then when you hit July, you can be switching back from warm-season to cool-season species,” he says. Producers can also add winter cereals as they will regrow through the year, facilitating rotational grazing, Elmy adds.

With an annual crop seed mix, not everything suits every area. Finn says that in southern Alberta, a producer can use more warm season grasses such as sorghum, Sudan grasses and millets. In northern Alberta or foothills areas with a cooler climate, producers would want some clovers, brassicas and Italian ryegrasses.

Crop farmers who don’t want weed issues need to watch what they’re seeding, says Finn.

“If they mix a blend of annual ryegrass and collards or something similar that will bolt in about 45 to 60 days, they’ll have a weed issue,” says Finn. “They need to choose long-period bolting crops that are not going to set seed in a crop rotation. When using oats, wheat, barley or triticale, make sure it’s a later-maturing variety.”

Producers planning a winter swath-grazing program, however, want it to all mature at the same time. Finn uses Winfred and Goliath forage rape, Hunter forage turnip, New York turnip, 4010 forage peas, and baler forage oats for winter swath-grazing because it’s a later-maturing oats. The later maturity gives the brassicas, forage peas and clover more potential growing time.

“You try to match the mix to what you need in your own program,” Finn says.

For fall or winter grazing, annual grazing will always beat corn on price, just in seed costs, says Finn.

“My winter swath grazing with brassicas in the mix runs about $35 per acre in seed, plus any fertilizer costs if needed,” Finn says, adding that he does a soil test every spring to determine fertilizer needs.

“With corn, however, the seed may cost $90 to $120 per acre. Then if the cattle are eating only the cobs, you are left with all that trash residue in the spring that you have to do something with,” says Finn.

It’s worth doing some homework and exploring the pros and cons of multiple options before deciding what and when to plant.

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