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Annual clovers to the rescue

The Berseem variety Frosty is not inhibited by alfalfa making it a good choice to boost patchy stands.

Annual clover may be just the remedy if your pastures and hayland are looking a little under the weather this spring.

Performance Seed, a newly established forage seed company at Lethbridge, Alta., is introducing two new low no-bloat annual clover varieties that show good potential as stand-alone crops or in blends for grazing, hay, silage or cover crops. Both are from the wholesale forage seed breeding company, Grassland Oregon, at Salem, Oregon.

Annual clovers offer the same nitrogen-fixing and feed-quality benefits as perennial legumes. The added advantage in some grazing and cropping scenarios is that Mother Nature kills annual clovers each winter, eliminating the need for tillage or herbicide applications to get the job done, says Performance Seeds representative Darrell Holyk.

When properly inoculated, nodules on the roots fix nitrogen from air in the soil to supply the plants’ requirements for growth. The nitrogen from plant biomass remaining after harvest or grazing is released into the soil as the plant material decays.

Both of these annual clover varieties have long, strong tap roots capable of breaking through hardpan layers to tap into nutrients deeper in the soil and create channels for air and water infiltration. The tap roots break way for the plants’ own root systems and those of companion crops to expand, versus some perennial clovers that form masses of shallow roots that rob topsoil moisture from reaching other plant roots below.


The Berseem variety, Frosty, is noted for its compatibility with alfalfa because of its similar structure and growth habit, but more so because it is not affected by the natural substances alfalfa releases to inhibit growth of nearby plants (alleleopathy).

These traits make Frosty a nice choice for boosting current-year yield potential when planted into patchy or thin alfalfa and mixed-forage stands. It’s also popular south of the border as a nurse crop to establish new alfalfa fields.

Holyk suggests Performa LeguMax as an option for longer-term rejuvenation. It is a blend of perennial legumes including mountainview sainfoin (45 per cent), cicer milkvetch (20 per cent) and alfalfa (five per cent), with Frosty making up the remaining 15 per cent to protect the young perennials.

For annual hay, silage or swath grazing, he recommends sowing Frosty at five to seven pounds per acre with your choice of cereal, but reducing the seeding rate of the cereal by 25 to 30 per cent so that the canopy doesn’t shade the clover too much. Harvest at the best time for the cereal crop.

Performa annual forage mix is the company’s blend of annual grasses, brassicas and legumes (Frosty, Fixation and hairy vetch) that fits into a season-long rotational grazing system. It can be planted with 30 pounds per acre of an annual cereal and forage peas added at 10 pounds per acre if you like.

The suggested seeding rate for planting Frosty as a monoculture is 15 pounds per acre if putting it into the ground with a drill and 25 pounds per acre if broadcasting.

This crop does best on loamy and silty soils with pH ranging from 5.2 to 7.8.

The window to get the crop in the ground is fairly wide, from April 15 to May 15 in southern Prairie regions, allowing flexibility to give waterlogged soils time to dry. Sow early on the moisture, or hold off for spring rains. Once established, it is moderately tolerant of waterlogged field conditions.


Fixation is a Balansa variety. Balansa clovers are said to be the most versatile of the annual clovers because they perform well in all types of soils from heavy clay to sandy, through a wide pH range from 4.5 to 8.5, tolerate moderate salinity, and withstand waterlogged soils and short periods of flooding.

Both varieties use strong tap roots to reach nutrients deep in the soil while nodules fix nitrogen.

Fixation is suggested as a good choice for intensive grazing systems because of its quick growth in spring and early summer. Well-established plants recover quite rapidly compared to other clovers because of its cluster of multi-branched stems growing out and then upward from the rosette. It is a prolific seed producer and should be managed to prevent seed set before a killing frost.

This variety specifically has been observed to be quite tolerant to cold, Holyk says. Its ability to withstand late-spring and early-fall frost likely varies depending on its stage of growth, field and moisture conditions, and whether there is a snow covering for insulation.

With its big, branchy growth habit, yields were usually, but not always, higher than Frosty clover in a two-cut haying system in the northern U.S.

Uses are the same as for Frosty clover, with the addition of being an excellent forage choice to smother weeds when grown as a monoculture cover crop.

Smaller seed size allows for a low seeding rate of five pounds per acre when planting with a drill or eight pounds per acre for broadcasting. In mixes, plan for three and five pounds per acre, respectively.

Performance Seed works with Verdesian Life Sciences in Cary, North Carolina, to supply appropriate inoculants and/or seed coatings for its perennial and annual legumes, cool- and warm-season grasses, and forage brassicas.

For more information or to receive a catalogue by mail call 1-888-808-2898.

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