Be careful when applying manure to established alfalfa fields, warns Bruce Anderson, University of Nebraska extension forage specialist.
Manure is an excellent source of nutrients, and it can enhance biological activity and soil physical properties. But it also can damage the crop, says Anderson.
Liquid manure can burn leaves, and dry manure can smother plants if applied too heavily or in big chunks. Manure can also spread weed seeds, and its nitrogen can make grasses more competitive with the alfalfa plants. In addition, manure application equipment can damage alfalfa crowns and compact soil.
If you need to apply manure to alfalfa, Anderson offers these suggestions:
Apply less than 3,000 gallons of liquid manure or 10 tons of solid manure per acre. If the manure is dry, adjust the spreader to break up chunks.
Spread it immediately after a cutting to minimize direct contact with foliage.
Only spread manure when fields are dry and firm to limit soil compaction and avoid damaging plant crowns.
Apply manure to fields with lots of grass if you want to stimulate grass yield, or choose fields with little grass if you want to minimize grass competition.