EAST LANSING -

President Barack Obama says signing the sweeping farm bill in Michigan makes sense because of its strong agricultural industry and few states better symbolize the nation's challenges during the past few years.

Obama told an audience at Michigan State University on Friday that the legislation boosts research at the East Lansing campus and other schools. Agriculture is Michigan's second largest industry behind manufacturing, which Obama says is "roaring again" after hard times and bankruptcies.

Read more: Obama signs farm bill that trims food stamps

The president says the nearly $100 billion-a-year bill passed after years of wrangling largely because of Democratic Michigan U.S. Sen. Debbie Stabenow, who spoke before him

Before his speech, Obama said he ate lunch with Detroit Mayor Mike Duggan. He says Duggan wanted everyone to know that "Detroit is open for business" despite undergoing bankruptcy.