Guidelines for Profitable Alfalfa Production
Field Preparation and Timing
• Test soil and apply corrective ag lime, N, P2O5, K2O and micronutrients. A proper pH is the single most important fertility factor for establishing and maintaining high yielding, productive alfalfa stands. Apply ag lime at least 12 months before seeding to achieve a desired 6.7-6.9 pH at seeding. A pH of 6.0 versus a pH in the 6.7-6.9 range can reduce the first hay year’s first crop yield by 30%. This yield drag continues for the life of the stand.
• Control perennial weeds such as quack grass before seeding.
• For Kussmaul Seeds’ marketing area, the spring seeding of alfalfa seed can begin as soon as a proper seedbed can be prepared. A proper seedbed is one that is smooth, firm, clod-free for the optimum placement of seed by the drill or Brillion seeder. Avoid working soils that are too wet to prevent compaction and crusting.
• Alfalfa stands can also be established by summer seedings. Keys include timing seedings with anticipated moisture and early enough in August to allow 6-8” of growth before the first killing frost. Seeding should be completed by August 10th in the northern half of Kussmaul Seeds’ marketing area and by August 20th in the southern areas.
• A seeding rate of 14-17 pounds of high quality alfalfa seed will usually produce adequate stand counts. Go 20% higher if direct seeding.
• Place seed 1/4 to 1/2 inches deep on medium and heavy soils and 1/2 to a maximum of 1 inch on sandy soils.
• Good alfalfa stands can be established with companion crops if the field is managed to the advantage of the alfalfa rather than the companion crop.
Germination and Emergence
• Germination will begin after an alfalfa seed has absorbed about 125% of its weight in water.
• Germination will begin when soil temperatures exceed 36°F. However, the ideal temperature range for germination is 65-77°F.
• Alfalfa seedlings are very tolerant of the cold through the first trifoliate leaf stage of growth. The first trifoliate usually develops about two weeks after emergence.
• Under normal conditions, only about 60% of the seeds planted germinate and emerge from the soil.
The period of time from emergence to the appearance of the first flower buds. A period 6-8 weeks for spring seedings and 9+ months for summer seedings.
• Nearly 60-80% of the seedlings that emerge, disappear during the
• Alfalfa is particularly vulnerable to the following diseases during the seeding stage; Aphanomyces Root Rot, Anthracnose, Common Leaf Spot, Downey Mildew, Phythium Seedling Rot, Spring Black Stem and Summer Black Stem. Growers can put the odds of a successful stand in their favor by planting resistant varieties, using seed treated with the Apron fungicide and following recommended agricultural practices.
• Seedling alfalfa, particularly under a spring seeded companion crop, is a prime target for potato leafhopper injury. Select resistant varieties
or monitor fields for the presence of potato leafhoppers and use chemical control as needed.
• Control competition from annual and perennial weeds.
Productive Mature Stands
• Alfalfa has a tremendous ability to produce maximum yield over a wide range of stand densities. Normally, new seedings should enter the first hay year with 25 to 30 plants per square foot.
• Alfalfa yield is determined by the number of plants in a given area, the number of stems per plant and the weight of each stem. The
maximum number of stems on a plant is set within 14 days after
harvest and declines as the plant ages.
• Maximum forage growth occurs when temperatures are between 50 and 80°F.
• The leaf to stem ratio is less for spring growth than mid-summer. However, summer growth will have greater lignification than
• When three harvests are taken during a growing season, the
relative yield ratios are 7:5:3. That is, if the first crop yields 3 tons/acre, then the second and third will yield approximately 2.1 and 1/3 tons/acre respectively. The relative yield ratio is generally 9:7:5:3 in a 4-cut system.
• The harvest schedule varies by variety.
• For optimum persistence, cut between first flower and 25% flower for each crop. Generally a 3-cut system.
• For high quality, cut at mid-bud and 28-33 day intervals thereafter. Do not harvest after frost. Usually a 4-cut system.
• For high yield and high quality, cut first crop at the bud stage, the second in 28-30 days and subsequent crops at 38 to 55 day intervals. Generally a four-crop system.
• Harvest is not advised between September-October 15th for any of the above cutting schedules.
• Each ton of alfalfa hay harvested removes approximately 14 pounds of P2O5, 58 pounds of K2O; and the calcium and magnesium found in 100 pounds of ag lime. This is the nutrient equivalent of 150 pounds of 0-10-40 fertilizer. Replace annually with top dressed mineral fertilizer or manure when feasible.
• Disease pressure during the early hay years of the rotation includes; Anthracnose, Common Leaf Spot and Spring Black Stem. Later in the hay years Bacterial Wilt, Fusarium Wilt and Crown Rot, and Verticillium Wilt join the assault. For long stand life, plant resistant varieties, maintain fertility and follow recommended agricultural practices.
• Monitor alfalfa stands for alfalfa weevil during May and June;
and potato leafhopper during June, July and early August.
Treat as recommended.
• Typically, stands that fall below 40 stems per square foot or 3 to 4 healthy plants per square foot are no longer profitable and should