The first step is to evaluate your current stand and determine the extent or severity of damage. This will help you to determine whether you should try to improve the existing stand or plow it up.

Seven to fourteen days after harvest or grazing, walk through your fields to evaluate your stand. Stop every 50-100 steps and count the number of plants in one square foot area. Make sure to count only the alfalfa plants, not weeds or grasses. Do this in about 20 different places in the field, then average the readings out.

Thick stands of alfalfa yield higher quality hay than thin stands. An ideal newly established alfalfa stand has a uniform stand of 20 or more plants per square foot. Later, that number will drop as the more aggressive plants expand and crowd-out smaller plants. When stands drop below 5 plants per square foot, plants tend to be more rangy and it is usually a signal to plow and plant to other crops.

If the land is suitable for row crops, this would be a great time to move along with the crop rotation. If the land is subject to erosion or you want to keep it in forage production for another year or so, overdrill with cool season grass or red clover.

20% to 40% stands

These stands will usually yield less than half their potential as hay unless there is a good stand of grass in the mix. Without grass in the mix, weeds can become a real problem. Rotate if the land is suitable or overseed to extend forage production.

If your stand is in this range, it is ideal for overdrilling orchardgrass, for example, at a 4-6 pound rate. If you are going to keep this field in alfalfa for a couple more years, add red clover in the spring as well. Both grass and red clover beat weeds.

These stands should produce satisfactory yields. However, if grazing, the holes in the stand should be filled with grass to prevent weed and wild grass invasion.

This stand is what we all strive for, especially as the stand ages. The only production restrictions here are soil quality, fertility, weather, variety potential, harvest systems and sufficient moisture.

Depending on the age of the stand, there are several options available for improving the current stand. If you have an older stand, fertilization can improve the stand. If the stand is less than one season old, you can consider thickening the stand by additional seeding.

Top-dressing fertilizer is a very important aspect of alfalfa production that is often forgotten. Whenever you harvest a crop, the fertility of the soil and stand is reduced, and it is necessary to replace the lost nutrients. These key nutrients are lime, phosphate, and potassium (potash). It is not necessary to apply nitrogen because legumes, such as alfalfa, produce their own nitrogen. Fertilizing an established stand has been shown to increase yields and improve persistence.

Sample your soil and follow the recommendations for fertilizer application provided by your crop consultant or local fertilizer plant. In addition, you can contact your County Agent for fertilizer application rates for your area.

A stand that is less than one season old can be improved by seeding to increase the plant population and thicken the stand. This practice is not recommended for older stands because remaining plant residue will cause a condition called autotoxicity. This is essentially an infection that causes stand failure or poor establishment. This is why you cannot follow alfalfa with alfalfa.

Thickening a new stand can be successful if you do it within one year. For example, if a spring seeding was not well established, you can seed that again late summer/early fall. If a late summer seeding did not do well, you can seed in the spring.

If you decide to thicken your stand, it is again, a good idea to soil sample and apply fertilizer.

When you are ready to seed, follow these recommendations:

• Use a no-till drill if possible.

• Seed to 1/4 to 1/2 deep.

• Use the same seeding rate as originally (12-15 pounds per acre.)

• If you are doing a late summer/fall seeding, follow the recommendations in the next column. (See Late Summer Seeding.)

Some situations may warrant that you plow up your existing alfalfa stand. If your stand is producing less than four tons per acre, or your crop rotation depends on that field, plowing it up and planting another crop is a viable alternative.

Plant a row crop if that field does not need to be returned to alfalfa as soon as possible. If other fields are not available for alfalfa acreage because of herbicide use, you could plant a small grain or vegetable crop with an early harvest. Once that crop has been harvested, you can do a late summer/fall seeding to return the field to alfalfa.

Late summer seeding can provide an option for establishing a healthy, productive alfalfa stand. Although late summer seeding should not replace the traditional spring seeding, it is a viable alternative in several situations.

• When a spring seeding has failed.

• When a small grain or vegetable crop was grown and harvested early.

There are several advantages to late summer seeding. Weeds and insect pest effects on stand establishment are reduced. Because of the approaching cold weather and frost, weeds and insects have little time to harm the new stand. Also, yields of late summer seedings in their first year of production can be higher than yields of spring seedings during the year they are established. A late summer seeding can produce yields equivalent to a 2– or 3-year old stand. Another advantage is that late summer seedings may be more successful than spring seedings on heavy, poorly drained soils because the soil is warmer and dryer, reducing the chances of root rot. Finally, seeding alfalfa in the late summer reduces your spring workload.

Several concerns with late summer seeding of alfalfa pertain to weather conditions. Lack of moisture can affect germination and seedling establishment. There is also the threat of cold stress or an early killing frost.

• Seed alfalfa 6-8 weeks before the average date of the first killing frost. August 1 thru August 15 is the ideal time in Wisconsin. Seeding after September first greatly reduces the chance of establishing a successful stand. Seeding too early increases the risk of hot, dry conditions that can impede germination and seedling development. Seeding too late will not give the plants adequate time to grow before winter.

• Test your soil and follow recommendations for soil pH, potassium, and phosphorous levels. The soil pH should be above 6.2 before planting.

• Adequate seed bed preparation is important. Minimize tillage to reduce soil moisture loss. Make sure the seed bed is firm. This may require going over the field after planting with the planter or a packer to improve seed-soil contact.

• It is not recommended to use a cover crop. This will only compete with the alfalfa seedlings for moisture.

• If necessary, apply an approved herbicide to control weeds.

• Seed at the rate of 12-15 pounds per acre and a depth of 1/4 to 1/2 inch.

• Do not harvest a late summer-seeded alfalfa in the fall. The plants’ root system will not have had adequate time to develop. The alfalfa will not smother out during winter, even if there is a large amount of top growth.

• Harvest the first crop the next spring at the mid-vegetative to early bud stage. Harvest later crops at the early flower stage to improve stand persistence.