America’s Alfalfa has filed for a patent for the first manure-tolerant alfalfa genetics.

In two years of testing at Waseca, MN, the company’s Ameristand 403T averaged 14% more yield and 18% better stand persistence under midseason manure application than other popular varieties.

The trials were conducted in 2001 and 2002 by JoAnn Lamb, a USDA-ARS research geneticist at the University of Minnesota. Four applications of 5,000 gallons/acre of liquid manure were made each year. Manure was applied 8-10 days after each cutting.

Manure tolerance apparently can be enhanced through genetic selection, says Lamb. Ameristand 403T was developed during a 10-year breeding program to select parents that survived intensive grazing and traffic.

"It appears that alfalfa varieties that have been exposed to the rigors of continuous grazing with frequent defecation and urination by cattle are different and show greater tolerance to the stresses caused by midsummer manure applications," she says.

"During the growing season, alfalfa fields are the only practical alternative most livestock producers have to dispose of lagoon effluent," adds Jim Moutray, America’s Alfalfa research director. "It certainly seems to make economic sense to plant a variety that research shows will produce bigger yields with a longer stand life under manure."