Animal performance and plant production from continuously grazed cool-season reclaimed and native pastures

Abstract

The Surface Mining Control and Reclamation Act of 1977 requires that surface-mined land be revegetated with "the same seasonal variety", meaning species of the same season of growth as the species native to the area. Our objective was to compare season-of-grazing use of pastures comprised of introduced cool-season species with pastures comprised of a mix of native warm- and cool-season species. The study was conducted on surface-mined land near Center, North Dakota, dominated by smooth bromegrass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L.) and on adjacent unmined mixed prairie. Pastures were 1.86 ha in size and stocked with 2 yearling steers (Bos spp.) each. Grazing was started in May or June and ended in late September or early October for 96 days in 1982 and 126 days each in 1983, 1984, and 1985. Liveweight gain increased from mid June through August and then remained constant on all pastures. Herbage dry matter yield from reclaimed pastures was equal to or greater than yield from native pastures each year. The season-of-grazing use was no different for reclaimed cool-season pastures than for native mixed prairie, and there was no evidence that species with the same growing season as those native to the area were necessary to provide season-long grazing use. Cool-season forage species are easier to seed, establish, and less expensive to buy and can be used to revegetate surface-mined land for season-long grazing use.