Good quality alfalfa is the cornerstone of any dairy farm forage ration. With the challenging planting season we have just experienced, corn and soybean planting took priority. However, we can seed alfalfa for next year and beyond anytime during the summer as long as we have it in the ground by the first week of August. I've put together some of the questions and answers that have come across my desk in recent years regarding good alfalfa management. The University of Wisconsin has an excellent website with a wide variety of information on raising excellent quality alfalfa. Information contained in this article came from their website at www.uwex.edu/ces/crops/uwforage/alfalfa.htm
Consider these factors:
A. High Yield Potential: Forage yield drives the economics of alfalfa production. While it may appear that two varieties perform similarly, only a 1/10 ton lower yield per cutting can result in substantially lower profitability over the life of a stand.
B. Disease resistance: Multiple disease resistance is an important risk management strategy. Many diseases do not affect the health of the alfalfa plant each year, but having disease resistance can prevent catastrophe and will likely show in large yield differences at least once in the life of the stand.
C. Stand persistence/winter survival: Healthy alfalfa plants that persist throughout the productive life of the crop results in higher profitability. Stand persistence is often influenced by plant health, insect management, soil fertility, and climatic conditions.
How about "cheap" alfalfa seed? You get what you pay for. We know that University trials have used Vernal alfalfa as a standard check variety for many years. Vernal has not performed as well nearly as well as modern varieties, especially in recent years. This variety may keep up for a cutting or two when growing conditions at optimum, but when stress occurs, performance lags.
In medium to high yield environments, Vernal comes in at 75-80 percent of top varieties. The cost of good seed quickly becomes a minor issue when looking at production over the life of the stand. Some "cheap" alfalfa seed is really a blend of varieties. Often in years of surplus seed production, several alfalfa varieties are blended together and sold as an unnamed seed blend. The blended seed varies by dealer and company. The problem is that you never know what genetics have been included and at what ratios. Thus, there is a chance of having poor varieties in a blend.
How about applying manure to alfalfa? Manure has been traditionally been targeted for use on corn acres because corn uses and needs all of the nutrients supplied by manure, especially nitrogen. In recent years, there has been a trend towards using manure on alfalfa acres during the years of alfalfa production.
We know that alfalfa CAN use all of the nutrients and alfalfa also has the convenience of being available during the growing season. Also, we know that phosphorus-based manure management plans may limit the amount of manure applied to corn.
Most commonly, manure applications occur during the fall of the terminal alfalfa year. This means that the alfalfa is ready to be rotated back to corn production and manure is applied before tillage. There have been some documented cases of gross over application of nutrients that can cause some environmental hazards and cost the producer money due to additional and unnecessary fertilizer purchases.
Applying manure to alfalfa prior to seeding breaks tradition from the standpoint that manure nitrogen is being applied to a legume. However, such applications can result in significant phosphorus (P) and potassium (K) contributions for alfalfa establishment and in subsequent production years.
The application of manure to alfalfa prior to seeding should only be used where the crop is direct seeded or the companion crop is removed as forage. Applying high rates of manure where the companion crop is harvested as grain often results in significant lodging of the small grain.
Finally, manure can be applied to established alfalfa, if we follow a few guidelines. First of all, manure applications need to be made immediately after alfalfa harvest to reduce the risk of plant damage from both salt burn and wheel track damage. Don't apply more than 3,000-5,000 gallons per acre of liquid manure or about 10 tons of solid dairy manure to avoid damage to the established stand.