Applying as much as 12,000 gallons of liquid manure or 50 tons of dry manure per acre before planting alfalfa can boost yield more than commercial fertilizers at the same nutrient levels, according to Bruce Anderson, University of Nebraska extension forage specialist.
The nitrogen in the manure probably won't be utilized. But manure is also rich in phosphorus, potassium, sulfur and many micronutrients that alfalfa needs in large quantities, Anderson points out. Yield also increases on both low- and high-fertility soils with manure, while only low-fertility soils respond to commercial fertilizer. The increases may be due to other factors, such as improved soil tilth, increased soil microbial activity, micronutrients and early nitrogen availability, he says.
Growers who plant a companion crop like oats, to be harvested for grain, should not apply a heavy level of manure before seeding alfalfa because the companion crop can lodge and smother alfalfa. If the companion crop is cut early for hay or silage, however, it should be fine.
Soil and manure tests can determine how much manure to apply. Use tillage to mix manure well into the soil, and prepare a firm seedbed so new alfalfa seedlings will emerge rapidly and vigorously.
Plan your weed-control program carefully, since manure can stimulate weed seedlings. Proper timing of seeding, firm seedbeds and herbicides or clipping can control weed pressure, according to Anderson.
Source: Nebraska Crop Watch Newsletter.