The department's actions will allow farmers to feed their livestock on land that would otherwise lie idle.

CRP participants receive annual government payments to set aside their land to prevent erosion, provide wildlife habitat and improve water quality.

A drought throughout the Plains states has withered crops and forced many ranchers to take their cattle to slaughter earlier than planned. The extra supply of beef is one factor blamed for a fall in cattle prices in recent weeks.

Haying and grazing are authorized until Aug. 31 or until disaster conditions no longer exist, whichever comes first.

USDA said CRP participants who are not affected by the drought or do not own livestock can make their land available for grazing or donate hay to those in need.

The 18 approved states are: Arizona, Colorado, Georgia, Idaho, Kansas, Minnesota, Montana, Nebraska, New Mexico, North Carolina, North Dakota, Oklahoma, South Carolina, South Dakota, Texas, Utah, Virginia and Wyoming.

CRP annual rental payments will be reduced 25 percent to account for the areas hayed or grazed unless the hay is donated, USDA said. At least 50 percent of the CRP acreage must be left unhayed and 25 percent left ungrazed.