"The U.S. Department of Agriculture (USDA) offers several programs to help farmers recover financially from natural disasters, including drought and floods. All the programs have permanent authorization, and only one requires a federal disaster designation (the emergency loan program). Most programs receive mandatory funding amounts that are 'such sums as necessary' and are not subject to annual discretionary appropriations. The federal crop insurance program offers subsidized policies designed to protect crop producers from unavoidable risks associated with adverse weather and weather-related plant diseases and insect infestations. Policies must be purchased prior to the planting season. Eligible commodities include most major crops and many specialty crops (including fruit, tree nut, vegetable, and nursery crops), as well as forage and pastureland for livestock producers. The Agricultural Act of 2014 (2014 farm bill; P.L. 113-79) enhances the crop insurance program by expanding its scope, covering a greater share of farm losses, and making other modifications that broaden policy coverage. Producers who grow a crop that is currently ineligible for crop insurance may apply for the Noninsured Crop Disaster Assistance Program (NAP)."
CRS Report for Congress, RS21212
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html