José Arias, alfalfa seed production director for Forage Genetics International, says there are many differences, but two major differences come to mind: Water and plant density.
Arias says one difference is alfalfa forage production will require as much as a three-acre foot of water, and alfalfa seed production requires about half the amount or less.
Plant density is the other difference. Typically for alfalfa hay production, growers are planting anywhere from 20 to 25 pounds of seed per acre, and in seed production you would plant 1 to 2 pounds of seed per acre.
In order for the seeds to grow adequately, there are certain climate conditions that are favorable.
Doug Gross, alfalfa operations manager for Dairyland Seed Co., Inc., says alfalfa grown for seed requires an arid and dry climate.
He says a lot of the alfalfa seed producers can be found in arid areas of Idaho, Washington, Oregon, California, Nevada, Utah, Montana and Wyoming.
In these arid areas you will find specific types of soils, which also help the alfalfa seed to grow more efficiently.
Gross says alfalfa grown for seed is somewhat forgiving when it comes to soil conditions. “Ideally, you’d like the pH to be in the 6 to 8 range and that’s where it will grow best,” he says.
Fertile soil is obviously a plus, but alfalfa can be grown in a variety of soils.
Arias says soils that are well-drained are also necessary. “Well-drained soils decrease stress for alfalfa plants,” he says. If soils are wet and soggy, it inhibits proper flowering, which is key for pollination and overall success.
Arias says field burning is necessary to eliminate leftover residue on the surface from harvest and to help control pest populations.
Some areas of alfalfa production don’t even have the option of field burning due to regulations, but it could certainly be beneficial.
In addition to soil conditions and climate, certain pests are needed in order for successful alfalfa seed production.
When they’re buzzing around your food on the picnic table, they can be a real “pest;” however, without bees, alfalfa seed production would be nearly impossible.
Gross says pollinators are key to alfalfa seed production. “There are some areas that may have naturally occurring pollination by wind, but to really be successful you need bees.”
Gross says the majority of alfalfa seed producers use the leafcutter bee, and many growers have domesticated the bee and have learned how to manage it to maximize its pollination efforts.
Gross says some areas still use the honeybee, but it requires a longer season to pollinate. California is primarily a honeybee user.
However, many California growers are augmenting their honeybees with leafcutter bees to shorten their pollination season.
He also says, the alkali bee is still seen in Washington alfalfa seed production areas.
Tim DeRuwe, an alfalfa seed producer in the Walla Walla Valley in Washington, says running somewhere between 3 to 4 gallons of bees per acre will make for successful alfalfa pollination.
“We must manage the alkali bees and keep them going for successful pollination,” DeRuwe says.
DeRuwe says he will still buy quite a few leafcutter bees. He thinks of them as an “insurance policy” so he can guarantee a pollinated crop.
The bees are “pests” that are certainly required for alfalfa seed production, but there are some pests growers may need to worry about.
Arias says the biggest problem in alfalfa seed production worldwide is insect management. “The reason being because of our bee pollinators that we must have in the alfalfa fields working, and at the same time we have unwanted Lygus insects, which feed off of the plants.
The Lygus attack the buds, flowers and seed. Controlling these areas is key, or seed yield will be significantly decreased.”
Gross says there really aren’t a lot of issues when it comes to growing alfalfa for seed. Since it is in a dry, arid climate, growers don’t have to worry much about molds and mildews.
If you’re growing the crop in Canada it may be slightly wetter and a fungicide may have to be applied to prevent those diseases.
After the seeds are harvested and you don’t have to worry about them growing any more, there are a few steps for cleaning and packaging the seeds.
Gross says there are a few key pieces of equipment used in the cleaning process. The equipment necessary for the cleaning process includes a screen cleaner, a gravity deck and a rice roll.
The screen cleaner will sift and scalp the seed. From there it will go to a gravity deck, which will use the weight of the seed and separate all the seed into different grades.
Alfalfa seeds are usually different sizes and weights when compared to most weed seeds that may have found their way on the production line. Therefore, the gravity deck is essential.
After the gravity deck, the seed goes through a rice roll, which is a velvet roll that has two rolls that go side-by-side in opposite directions. The rollers will kick out any rough materials that go between the rollers while the alfalfa seed goes to the bottom and is packaged.
Gross says there are many types of bags, but it is important to have a bag that will not allow contaminants to enter. A good bag includes an outside paper layer with a plastic liner or a polylaminate bag, which is more durable but also more pricey.
In terms of labeling on bags, it’s important to know where the seed comes from. It’s actually required by the Federal Seed Act to correctly label the product with the origin, variety and grade.
After growing, harvesting and packaging, there is only one thing left to think about, and that is the next growing season.
Gross says after a growing season is complete, it is important to restore the water table. The alfalfa plant is going into the winter and will still need adequate moisture.
For example, DeRuwe will give a fall application of water in either October, November, December or sometimes even January. “We will normally run seven-gallon nozzles at 48-hour sets, and that’s what we do to build up the profile,” DeRuwe says.
DeRuwe says the established deep-running root system will find the water when the growing season returns. If the alfalfa plant is in its first growing season, more fall water applications will be needed.
Right after the winter months, DeRuwe will apply fertilizer. Then he’ll do extensive field burning to burn up leftover stubble from last season’s crop and to also kill disease and unwanted insect populations.
Around the first part of March, DeRuwe will run another 48-hour water application, and in most cases that will be enough water for alfalfa to grow during the season. FG