August Alfalfa Seeding – Best Management Practices

When talking with alfalfa producers this time of year, the term “fall seeding” gets used often. To set yourself up for success, these “fall” seedings should really be planted by August 15th. The reason we recommend seeding by this date is that seedlings need adequate time to grow a root system that can store enough carbohydrates for winter survival. When seeded later, the plants are at risk to a killing frost that may occur before root systems are properly developed. This greatly increases the risk for uneven/thin stands or winterkill.

August seedings provide livestock producers an avenue to spread manure which can be a huge advantage to some by this time of year. At this time, application methods are not as important compared to simply getting enough fertility applied. Ahead of alfalfa we recommend fertility levels of 175+ ppm K, 25 ppm P, and a soil pH of at least 6.8. When using commercial fertilizer, use rates that will increase field fertility to these levels based on soils samples from a given field. Applying elemental S at this time at a rate of 12-20 lbs. is an excellent way to set yourself up for a great crop the following year. Apply necessary amounts of lime, manure or commercial fertilizer prior to preparing the seedbed.

Just like spring planting of alfalfa, we recommend rolling the field, planting the seed with any type of drill suited for alfalfa, and completing the job with a final pass with the roller. In areas with high organic matter or with mellow soils, three passes with the roller may be ideal. Ensure that the seedbed is firm enough by walking on the field. If your shoe print is only 1/8th of an inch deep, you are ready to plant. Seed at a rate of 16-20lbs./acre.

Other Considerations
The greatest challenge when seeding alfalfa this time of year is the potential for dry weather. To minimize this threat, avoid planting a cover crop. This is especially true with conventional varieties. If the weather turns dry after seeding, a cover crop can easily out-compete the alfalfa for water. If the alfalfa planted is conventional, you cannot use an herbicide to kill back the cover crop if excessively dry weather occurs. If planting a RoundUp Ready variety with a cover crop, use an application of RoundUp about 30 days after planting.

When done correctly, August seeding of alfalfa can be a great option for alfalfa growers. The key to this method is planting your alfalfa by August 15th. Do not harvest the alfalfa until the following spring as new seedings are especially susceptible to winterkill. If you follow these simple guidelines you will be rewarded with a nice crop the following growing season.