"Nurse Crops" for Alfalfa

Hay prices are up! Are you planting some alfalfa this spring? Using oats or another companion crop? Let's examine the advantages and disadvantages of your options.

Alfalfa often is seeded with a companion crop like oats to control weeds and erosion. In contrast, clear seeding alfalfa alone, without a companion crop also works well. A preplant herbicide like Balan or Eptam often is pre-plant incorporated to control weeds in a clear seeding, but herbicide isn't always necessary. So which method is better?

Your own needs and objectives determine whether a companion crop or a clear seeding is better for you. I prefer clear seeding because alfalfa production begins much sooner, with 2 to 4 tons possible the seedling year, usually in a single cutting. Companion crops lower alfalfa yield the first year, and often reduce stand density. Yields and stands in subsequent years are almost always better with a successful clear seeding than when using a companion crop.

Some people use the term "nurse crop". Nothing could be further from the truth! That's because companion crops, like oats, don’t nurse. They steal. They are weeds, robbing alfalfa seedlings of moisture, sunlight, and nutrients during the seeding year. Although they compete with the seedling alfalfa, on erosive ground a companion crop can be necessary. I remember an example of a clear seeded field south of Arco that was seeded on a pivot. It emerged perfectly, and was in the 1-3 trifoliate leaf stage when we had one of our spring wind storms. Just about every plant was cut off by the fine flying sand particles, except those behind the occasional pebble or clod. A "companion" crop or some other management to reduce the impact of blowing sand would have been appropriate!

When planting the companion crop in alternate row, cover
every other opening in the large seed box and set the drill for
twice the desired (l0 lbs/acre) of seed.

Many of us want just alfalfa for the dairy trade so, plant only alfalfa. If erosion is a problem, include just 10-15 lbs per acre of oats with your alfalfa. Then kill oats early using Poast Plus or Select herbicide, or Roundup if your alfalfa is Roundup Ready. Another alternative that seems to work pretty well is to plant the oats in every other line and the alfalfa in every line. This provides lots of light and the first crop will be a pretty good alfalfa-oat mix. Next best is to hay oats early rather than taking grain.

Likewise, if you want oats, plant only oats. Harvest the grain and/or hay. Then seed alfalfa into fine firm seed bed that the oat stubble provides in early August. Turn the pivot on immediately and the alfalfa will be up in 4-5 days. Once it reaches the first trifoliate leaf it will be pretty safe from frost.

Avoid planting a weed with your alfalfa crop. Try a clear seeding in the spring, particularly if you have a pivot and little likelihood of erosion. Or seed the alfalfa into the almost perfect legume seed bed that you will have after taking off the grain hay. You will end up with more alfalfa and a better stand in the long run.

By Chad Cheyney
Butte County Extension Educator
208-527-8587

Adapted for central Idaho from an article by:
Bruce Anderson
Extension Forage Specialist
University of Nebraska
voice: 402/472-6237