When planting perennial hay fields, decisions made now will affect your harvest for several years. So, it pays to put a little extra thought into making sure you start the crop off right.
When planting alfalfa into less than ideal soils, seeding forage mixes is a good idea to help cover places where alfalfa may not persist well. Sticking with legumes, red clover and birdsfoot trefoil can provide forage in fields where drainage or pH is inadequate to support an alfalfa stand. Forage grasses can boost yield and digestible fiber when mixed with alfalfa and provide extra stand longevity as legumes begin to die out. As with straight grass plantings, once the legumes begin to run out in a field, nitrogen fertilizer can be applied to substantially increase yields.
When considering your choice of alfalfa, make sure you have the right seed. Pay attention to disease resistance. In particular, Phytophthora root rot is a hazard during the first year, especially in wet soils. Bacterial and Verticillium wilt can pose a threat in the later years of the hay crop’s life. Another good trait to look at is leafhopper resistance. Potato leafhopper can cause significant damage to alfalfa stands, especially during a summer dry spell or drought. Leafhopper resistant alfalfa varieties can stand up to much higher leafhopper populations before suffering damage. This higher tolerance can buy you a few extra days before you need to spray, or even remove the need to spray entirely. Be ready to scout and take action during the seeding year, however, as the resistance traits offer little protection during initial establishment. The newest major trait on the market is low lignin alfalfa. Reducing the lignin in alfalfa shows promise for increasing yields by allowing 5-7 days more growth between cuttings while still maintaining the forage quality of an early cut. Extra care is needed establishing low lignin varieties because they seem to have lower seedling vigor compared to traditional varieties.
Once you have picked out your seeding mix, it’s time to consider the field itself. The first thing to consider about your field is the pH. The proper pH is critical for stand establishment and longevity. A pH of 7.0 is ideal for alfalfa hay. When the pH of a field falls below 6.5, alfalfa suffers, grows less vigorously and is more susceptible to disease and injury. For other legumes, a 6.5 pH is adequate. Also consider your field’s fertility. Medium or higher phosphorous levels help insure good stand establishment in legumes. High potash levels increase the plant’s ability to tolerate drought and disease. If levels are low, fertilizer or manure is recommended before or during planting to help feed the plant as it develops.
After you have selected an appropriate field, preparing the soil is key. Since seedings are planted shallow, the seedbed should be firm before planting starts. To insure the seed gets enough water, you need to create capillary action, and that requires firm ground. If you can bounce a basketball on the field, it’s firm enough. If you can easily press the heel of your boot into the soil, it’s probably too soft. When a field surface has a fluffy texture, water cannot get to the seed effectively. The seeds are left waiting for a lucky shower that might not come. If your alfalfa only seems to sprout in your tractor’s tire tracks or on the headlands, the seedbed wasn’t firm enough. It’s all about a good foundation.
For management tools and situation-specific seeding recommendations, visit forages.org.