August 4, 2010

August 3, 2010

Sometimes an alfalfa field is your only option if you have manure to spread during summer, but it can cause problems. Liquid manure can burn leaves due to salt injury, and dry manure can smother plants if it is applied too heavily or in large chunks. Manure can spread weed seeds, and the nitrogen in manure can stimulate grasses already in the alfalfa to become more competitive. Also, manure application equipment can damage alfalfa crowns and compact soil.

If other land is available for the manure, spread it there, but if you have no other choice, follow these suggestions:

1. Apply less than 3,000 gallons of liquid manure or 10 tons of solid manure per acre to minimize salt burn or smothering. If manure is dry, adjust the spreader to break up large chunks that can smother growth.
    
2. Spread manure immediately after removing a cutting to minimize direct contact with foliage.
    
3. Only spread manure when fields are dry and firm to limit soil compaction and avoid wheel traffic damaging plant crowns.
    
4. Apply manure to fields with lots of grass if you wish to stimulate grass yield. Conversely, if you want to minimize grass competition, select fields with little grass.

Manure is a great nutrient source and can enhance biological activity and soil physical properties, but be careful when applying it to alfalfa so you don't do more harm than good.

Bruce Anderson
Extension Forage Specialist