There are a number of factors to consider when planting and maintaining an alfalfa field. Are you establishing a new crop or seeding into an existing one? What has your crop rotation looked like? Have you also planned a companion crop to help support your alfalfa? Knowing the answers to these questions and planning accordingly will help ensure that your silage is in the best shape it can be come harvest time.
Establishing a New Alfalfa Crop
Though you’ve probably already seeded by now, any advice is good advice, because there’s always a new season around the corner. We’ve discussed how to prep your soil and the importance of picking the right seed, but how do you ensure the success of a new alfalfa stand after it’s in the ground?
Weed management is issue number one. If you haven’t seeded yet, an all-encompassing herbicide is usually a good idea to take care of those tough over-winter weeds. Thorough tillage also helps prevent those weeds from taking hold. But after seeding in a new stand, it’s usually a matter of picking the right herbicide. Later in the season, you’re not only worried about weeds; volunteer crops like wheat can be devastating to newly established alfalfa, significantly reducing yield. Make sure your herbicide is clearly labeled For New Alfalfa.
You can find much more specific info about herbicides in The University of Wisconsin’s Alfalfa Management Guide.
A nurse or companion crop also helps a new alfalfa stand gain its footing. Companion crops can help control erosion, suppress weeds and provide extra value for a newly established field that may run thin the first year. If you’re using a Roundup Ready alfalfa, a companion or nurse crop is an even better idea because it will be easier to control early in the season.
Seeding an Existing Alfalfa Field
Second or third-year alfalfa stands can struggle for several reasons. A rough winter for a first-year field can lead to a thin second-year crop, so it may make sense to “thicken” your youngish stand with a grain, ryegrass, legume or clover. If your stand is less than a year old, you can overseed with more alfalfa, but that’s not recommended for stands that are older due to autotoxicity, a defense mechanism that makes alfalfa plants release compounds that are toxic to other alfalfa plants of the same species. It’s essentially a way for a plant to keep other plants out of its space.
Overseeding with legumes or clover can improve your alfalfa silage’s nutrient qualities, while cereals or grasses will add to your tonnage.
Eventually, it will be time to consider rotating out of alfalfa in the offseason. Making that choice relies on a number of factors, from your farm goals to overall yield quality. There are a few methods that will help you determine when it’s time to rotate, but the most obvious indicator is your yield. Is the stand producing enough to meet your needs? If not, it might be time to switch and preserve future stand potential. You can also count your stems with they are 4-6 inches tall and compare the number to the previous year or compare to your current yield requirements and decide if the stand is meeting your needs.
In the end, management of your alfalfa stand is all about making sure that you meet the needs of your animals. If your forage requirements fall short, a change in practice is necessary. If you have any questions about alfalfa management, contact your favorite BONSILAGE expert.