Level Benches for Forage Production in the Northern Plains

Abstract

Level benches 4- and 8-m-wide were constructed at the Wyoming Agriculture Research and Extension Center, Gillette, Wyoming 1970. Replicated benches and controls were seeded with Ladak alfalfa, Nordan crested wheatgrass, intermediate wheatgrass, and mixtures of Ladak alfalfa and crested and intermediate wheatgrass. Phosphorus (134 kg P2O5/ha) was applied to all benches and to the control. Ammonium nitrate was applied at 90 kg N/ha in May 1972 and 1977, and at 45 kg/ha in April 1974 to the benches and control, except those seeded to alfalfa alone. Snow trapped in the benches was not uniformly distributed because of the benches' northeast orientation. However, more soil water was available for plant use. The deep-rooted alfalfa was compatible with the shallow-rooted crested wheatgrass and seemed the best combination tested for forage production on level benches in northeast Wyoming. Construction of level benches is a practice that can ensure a dependable source of quality feed by trapping and holding snow for onsite use. Forage yields from the henches and the controls varied with years. During the 8 years (1970-1978) on the 4- and 8-m-wide benches, alfalfa yields averaged 3,420 and 3,813 kg/ha, respectively, and alfalfa and crested wheatgrass mixture averaged 3,560 and 3,855 kg/ha, respectively. Crested wheatgrass alone on 4- and 8-m-wide benches averaged 2,569 and 2,456 kg/ha, respectively, and on the 4- and 8-m-wide control averaged 2,382 and 2,786 kg/ha, respectively. Intermediate wheatgrass on the 4- and 8-m-wide benches averaged 2,329 and 3,425 kg/ha, respectively, and on the 4- and 8-m-wide controls averaged 2,565 and 3,262 kg/ha, respectively. Grass yields did not differ significantly when grasses were grown alone on the benches or on the control.