President-elect Barack Obama has tapped former Iowa Gov. Thomas J. Vilsack to be his agriculture secretary and will introduce Vilsack at a news conference today in Chicago, where he will also name Sen. Ken Salazar (D., Colo.) as his interior secretary, a senior Democratic official said.

Vilsack, 58, who dropped out of the presidential race in 2007 after a short-lived bid, initially backed Sen. Hillary Rodham Clinton but campaigned hard for Obama during the general election. Vilsack is well-liked by both environmentalists and food-industry leaders.

The Department of Agriculture develops and executes the nation's policies on farming and food safety.

Salazar, 53, will become a key player in setting the new administration's environmental, energy and land-use policies. The Interior Department is charged with conserving most federally owned land and managing programs related to Native American populations and territories.

Salazar, 53, who is Hispanic, practiced water and environmental law in the private sector for 11 years before serving as Colorado's attorney general. He was elected to the Senate in 2004.

Also yesterday, Rep. Xavier Becerra (D., Calif.) said he would stay in the House and pass on becoming U.S. trade representative in Obama's administration.