DES MOINES, Iowa (AP) -- A lawsuit filed in California is challenging the federal government's deregulation of alfalfa that is genetically altered to withstand the popular weed killer Roundup.

Attorneys for the Center for Food Safety and Earthjustice filed the federal lawsuit Friday in San Francisco arguing the U.S. Department of Agriculture's approval of Roundup Ready alfalfa in January was unlawful.

Attorneys for the groups say the USDA failed to provide adequate oversight of biotech alfalfa. They also say genetically altered alfalfa causes significant harm to the environment and conventional crops, and threatens the nation's organic industry.

A federal court barred the planting of Roundup Ready alfalfa in 2007. The U.S. Supreme Court lifted the ban last year.

USDA officials say they are reviewing the lawsuit.