Farmers' bulletin (United States. Dept. of Agriculture); no. 1511

"This bulletin deals with those cultivated forage crops that seem of greatest promise for the dry-farming districts of northern Nebraska and the Dakotas west of the ninety-eighth meridian. Frequent crop failures in the more arid portions of these States result from a low annual precipitation, the irregularity of its amount and distribution during the growing season, and high evaporation. Under conditions of extreme drought, cultivated crops can seldom be economically substituted for native vegetation, and the utilization of such lands for grazing and the cutting of wild hay is most generally advisable. Greater forage production on the better lands may be effected by growing certain cultivated legumes, grasses, and roots." -- p. ii