Northern Prairie Wildlife Research Center
The value of good grassland habitat to the welfare of other game species has been well established through published studies and practical experience of wildlife managers. One of the most extensive upland cover programs in North America was the U.S. Department of Agriculture's Soil Bank Program in the 1950's and 1960's. During the peak years of this program (1960-61), 28.7 million acres of cropland were retired from production of cereal grains and planted with introduced grasses and legumes as a cover crop. Haying or grazing was not permitted. In North Dakota, 2.7 million acres were in this program in 1960 and these undisturbed acres of seeded grasslands were excellent habitat for many species of wildlife. Pheasant (Phasianus colchicus) populations in South Dakota increased from 4-6 million birds to 8-11 million birds during the Soil Bank period (Dahlgren 1967). In the 1960's the Cropland Adjustment Program (CAP) provided similar benefits but on fewer acres (Jaenke 1966). In 1967, about 2 million acres were idled under this program in the United States of which 210,000 acres were in North Dakota. The value of habitat developed under these land retirement programs for ring-necked pheasants, sharp-tailed grouse (Pedioecetes phasianellus), and greater prairie chickens (Tympanuchus cupido) was indicated by several studies (Dahlgren 1967; Gates et al. 1970; Kirsch et al. 1973).
The use of CAP fields for waterfowl nesting was affirmed in north-central South Dakota (Duebbert 1969; Duebbert and Lokemoen 1976). Studies at scattered locations elsewhere in the United States have shown that habitat created by planting introduced cool-season grasses and legumes and leaving them undisturbed provided a valuable cover type for nesting ducks and some other wildlife species. Duebbert and Lokemoen (1977) reported the utilization of upland fields of undisturbed tall, dense cover by nesting American bitterns (Botaurus lentiginosus), marsh hawks (Circus cyaneus), and short-eared owls (Asio flammeus). Many species of passerine birds utilized stands of seeded grasslands dominated by introduced cool-season grasses and legumes. Several thousand acres of such cover-commonly referred to as dense nesting cover (DNC)-have been planted on lands managed by the U.S. Fish and Wildlife Service in North Dakota, South Dakota, Minnesota, and Montana. Principal species of vegetation used to establish DNC have included mixtures of tall wheatgrass (Agropyron elongatum), intermediate wheatgrass (A. intermedium), alfalfa (Medicago sativa), and sweetclover (Melilotus officianalis). Where wildlife use of stands of seeded cover in the prairie pothole region has been evaluated the data have usually indicated positive benefits from the presence of the cover.
Another program that resulted in the establishment of seeded grass-legume habitat was the USDA Water Bank Program that started in 1972 (Womach 1977). In the prairie pothole region within North Dakota, South Dakota, Minnesota, and Montana about 340,000 acres of upland cover were under 10-year Water Bank Program contracts in 1979. The Water Bank has proven to be a valuable program for protecting wetlands and enhancing adjacent upland habitats.