Applying Manure Before Seeding Alfalfa

Applying Manure Before Seeding Alfalfa

March 21, 2008

If you're looking for a place to spread manure, a heavy dose before planting alfalfa can pay big dividends.

Applying manure before seeding alfalfa may seem counter productive since alfalfa is not likely to benefit from the nitrogen in the manure, but manure also is rich in phosphorus, potassium, sulfur, and many micronutrients that alfalfa needs in large quantities.

Research studies show that applying as much as 12,000 gallons or 50 tons of dry manure per acre before planting alfalfa can boost alfalfa yield more than commercial fertilizers at the same nutrient levels. And, yield increases occur on both low and high fertility soils with manure. Sometimes higher fertility soils do not respond to commercial fertilizer. Other factors like improved soil tilth, increased soil microbial activity, micronutrients, and early nitrogen availability may be the reason manure increases alfalfa yield so well.

Do not apply manure heavily prior to alfalfa seeding if you also plant a companion crop like oats that you plan to harvest for grain. It is likely to lodge and smother much of the alfalfa. A manure application will will work if you cut the companion crop early for hay.Use a soil test and a manure test to determine how much manure to apply. Then mix manure well into the soil using tillage, making sure to prepare a firm seedbed so new alfalfa seedlings will emerge rapidly and vigorously.

Also, 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.

Bruce Anderson
Extension Forage Specialist