Farmers will be able to plant Monsanto's Roundup Ready sugar beets this spring.
The beets have been genetically-engineered to tolerate Monsanto's Roundup herbicide.
The USDA initially approved the beets in 2005. The Agency was forced to re-evaluate its decision following a 2008 lawsuit filed by environmental groups, who say they will also challenge today's decision.
The Environmental Impact Statement evaluating the biotech beets is expected to be completed by the end of May 2012.
About 95 percent of the U.S. sugar beet crop is grown from Monsanto's Roundup Ready seeds.
For more, here's Monsanto's take on today's announcement.