His appointment was announced Tuesday by the Obama administration.
He has served as secretary of agriculture since 2003 and headed the Farm Service Agency during the Clinton administration, from 1993-2001.
Polansky said he will begin his new job later this month after he wraps up his work at the state agency. He said Gov. Mark Parkinson hasn't picked a replacement.
(Copyright 2009 by The Associated Press. All Rights Reserved.)