Alfalfa seed production

Growing alfalfa for seed can require intensive management, 
but can be rewarding. Learn the basics of alfalfa seed production

Alfalfa crop being harvested

Including alfalfa in a crop rotation can bring a number of agronomic benefits. Prairie farmers grow alfalfa for both forage and seed.

Randy Toman, a farmer near Guernsey, Sask., began growing alfalfa for seed production over a decade ago. With lighter land well suited to forage and legume production, alfalfa was a good fit for his operation. Adding alfalfa also served to extend Toman’s crop rotation.

With fewer farmers in the area producing seed than forage, Toman faced less competition and had the added benefit of income from the leafcutter bees he added to pollinate the alfalfa.

Similar reasons drew the Mennies into the business in the 1970s. “Farming was a bit of a struggle back then,” says Bob Mennie, production manager of Mennie Bee Farms Inc., near Parkside, Sask., “so we gave this a shot.”

Toman says, “Getting contracts to produce (alfalfa) seed is fairly easy now,” as alfalfa seed acreage has declined. Of the three prairie provinces, Saskatchewan sees the highest alfalfa seed acreage. In 2010, about 100,000 acres of alfalfa seed was produced in Saskatchewan, nearly 75 per cent of total Canadian alfalfa seed acreage.

Growing alfalfa seed

Choosing the right field is important. Alfalfa favours lighter, sandier soil, and flatter fields will see a more even maturity, as with other crops. More rolling land has the benefit of seeing a decent crop more consistently, as the hollows may produce more in drier years and the hilltops in wetter years while uniform fields are more inclined to yield well or yield poorly overall, depending on the weather conditions of each particular year.

Because of the limited chemical products registered for use on alfalfa, weed control is vital. “There are a few chemicals registered for alfalfa that do a pretty good job on most weeds,” Mennie says, but it can be difficult to rotate chemical groups to avoid developing resistance.

A good, clean field prior to seeding is key. “If you start with a clean piece of land, it’s much easier to maintain it rather than try to clean it up when it’s in alfalfa,” says Toman. Problematic weeds include sweet and red clovers, cleavers, wild oats, various grasses, kochia, night-flowering catchfly and Canada thistle.

Crop rotation is key. Keeping a field out of alfalfa production for two to four years is typically enough time to clean up weed problems.

The most common insect pests in alfalfa are lygus bugs, alfalfa plant bugs and aphids, with alfalfa weevil increasing in prevalence. It can be more difficult to control insects when the field in question is near to a field seeded to alfalfa for haying.

Leafcutter bees are released once the alfalfa begins to bloom. Spraying fields before this point is often enough to control the insects. “Once the bees have been released,” Toman says, “it is usually cost prohibitive to put on any kind of insecticide because you risk damaging a significant number of bees.” However, sometimes a late hatching or infestation of insects can necessitate a second or even third application once the bees are out in the field. According to Mennie, “when the right chemical is sprayed at night, there is minimal bee loss.”

Fungicides can usually control plant disease with relative success. However, in wetter years, alfalfa can grow very lush and forms a thick, dense canopy, meaning it can be difficult to control disease. “Burning the crop residue in the spring can make a huge difference for disease (control),” says Mennie, as does “light cultivation to break up the residue.” The worst diseases include black stem rot, sclerotinia and botrytis.

As a legume, alfalfa can fix nitrogen. But alfalfa is also perennital — the number of production years varies, but it typically between three and five. It is important to keep up an adequate fertility program to ensure that the soil has enough nutrients to sustain the crop for as many years as it is kept in rotation.

The number of production years varies but is typically between three and five years.

Alfalfa needs to be inoculated with a species-appropriate inoculant to induce nodulation on the root system of the plant and increase its ability to fix nitrogen. “The bacteria may already be in the soil, especially if alfalfa has been there before,” says Mennie, “but (inoculant) is very inexpensive,” so it is best to apply it to ensure that the bacteria are present in high enough numbers to induce good nodulation. Even when seed from seed is purchased coated with an inoculant, it can be good to apply additional inoculant.

Alfalfa can be seeded with or without a companion crop during its establishment year. The companion crop may be seeded at the same time as the alfalfa, as is done on the Toman farm. Their particular setup involves seeding alfalfa with canola, using a triple shoot on the seed drill to seed two rows of canola between every row of alfalfa. Alfalfa has a small seed like canola, and therefore seeding depth is shallow, about one-half to one-quarter inch deep. Alfalfa is seeded in 36 inch rows.

Alternatively, the companion crop can be seeded at a different time, at right angles to the alfalfa.

Seeding alfalfa with a companion crop limits weed control options with registered chemicals. The cover crop competes with the alfalfa for water and nutrients and, in some cases, can increase disease pressure. For these reasons, the Mennies tend not to use companion crops and seed alfalfa on a 12- to 24-inch spacing at a rate of 0.74 lbs./acre. If they do use companion crops, they choose less competitive crops like flax and peas

The Tomans still see a return their first year from companion cover crop.

Harvesting alfalfa

Alfalfa seed is considered dry at about 10.5 to 12 per cent; moisture levels greater than 13 per cent means the seed must be dried before storage. Harvest usually falls towards the end of the season, after most of the other crops have been harvested. Yields typically range anywhere from 200 to 400 lbs./acre.

Most farmers straight cut their crops after desiccating and let it dry down in the absence of a killing frost. Swathing alfalfa is rare. “Alfalfa can be very bushy in the swath, and because it has to be swathed fairly close to the ground, it has a high risk of blowing in the wind,” Toman says.

The crop threshes hard, requiring a fast rotor speed and tight concave opening. The seed is quite small. It can be difficult to initially find the right balance between wind speed and keeping the sieve settings as tight as possible without plugging the return system or blowing the seed out the back of the combine.

Alfalfa seed is a high value crop and should be treated as such, with diligent checking to ensure there is no spoilage. While alfalfa doesn’t require any special storage, the volume is small. “Keeping varieties separate can seem to waste space,” Mennie says. “Some small hopper bins are ideal for storing alfalfa.”

Benefits of alfalfa

There are several benefits to growing alfalfa:

1. Alfalfa only needs to be seeded in its establishment year, so there is less pressure on farmers during seeding in subsequent years.

2. Alfalfa spreads out the harvesting period.

3. In drier years, established alfalfa will thrive because its extensive root system enables it to scavenge for water unreachable to traditional crops. “We see the alfalfa seed as a bit of a safety net against drought,” Mennie says, noting that in wetter years, “it will hold its own as far as return.”

4. The diversified income for those who raise and sell their own leafcutter bees is also beneficial. Both the alfalfa seed and leafcutter bee markets are doing well at present.

Alfalfa seed production does have fairly high management requirements, particularly if the seed grown is certified seed, but the hard work can reap rewards.

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