It's Alfalfa Time Again!

The time to plant your alfalfa is quickly approaching.

“Fall is a great time to seed down alfalfa, but get it down before August 15,” said Craig Loen, Federated agronomist. “Planting soon gives the seed time to germinate, emerge and have the crown develop.”

There are several things to consider before you plant your alfalfa. 

“Make sure you have a current soil sample,” Loen said. “It should have been taken within two years of planting so you have time to adjust the nutrients in your soil. The soil test results tell us the pH of the soil. For alfalfa, the optimal pH range is 6.7 to 7.0.”

To raise that pH, ag lime is your best bet. However, the soil can take up to two years to receive the full benefit of ag lime applications. The pH level is vital, because alfalfa is a legume and doesn’t like acidic or alkaline soils. It likes neutral soils with phosphorus (P), potassium (K), and sulfur (S) falling in its optimum range.  

Seedbed preparation is also critical. “You want a firm seed bed,”  Loen said. “You should be able to dribble a basketball on the soil.” The seed should be pressed less than ½-inch into the soil, with good seed-to-soil contact. Rolling the soil before and after placing the seed is a good idea to achieve a solid alfalfa stand.

“Alfalfa should not be harvested in September,” Loen said. “You may take a cutting if necessary after first frost in October, or if you are planning on terminating the crop for next growing season. September is the month for fertilization. Alfalfa is a high nutrient-removal crop. To replenish the soil profile, you need to get the nutrients into the crown and roots of the alfalfa, so they are healthy. This contributes to the longevity of the stand life, winter hardiness, and winter kill.”

In the fall, adding P, K, S as needed is important. “A good source of sulfur for the alfalfa is gypsoil (SO4), which has 21% calcium, 17% sulfur, and it’s pH-neutral,” Loen said.

Contact your local Federated sales agronomist for more information and help in finalizing your fall alfalfa plans.