Senator Donnelly says he met with around 30 or 40 farmers.
Hoosier farmers planted more than one million acres of cover crops this year, up from virtually none in 2004.
New research shows cover crops planted in winter have environmental benefits.
Members of the 38th Infantry Division of the Indiana National Guard are set to be deployed to Cuba to help with Guantanamo Bay's detention operations.
In an effort to prevent long-term damage in unplanted fields, cover crops could be key for Indiana farmers.
Indiana Department of Agriculture officials say the so-called "green manure" helps soil recover faster if there is little rain.