Seeded wheatgrass yield and nutritive quality on New Mexico big sagebrush range.

Abstract

Establishment, yield, and nutritional quality of 'Nordan' crested wheatgrass (Agropyron desertorum [Fischer ex Link] Schultes), 'Fairway' crested wheatgrass (Agropyron cristatum [L.] Gaertner), 'Arriba' western wheatgrass (Pascopyrum smithii [Rydb.] A. Love), 'Luna' pubescent wheatgrass (Thinopyrum intermedium subsp. barbulatum [Schur.] Barkw. and D.R. Dewey), and 'Largo' tall wheatgrass (T. ponticum [Pod] Barkw. and D.R. Dewey) were evaluated on big sagebrush range (Artemisia tridentata Nutt. tridentata) in northcentral New Mexico during a 5-year study. All the above wheatgrasses showed high initial densities and long-term persistence. Wheatgrass yields across years and seasons during the last 2 years of study averaged 760 kg/ha compared to forage yields of 355 kg/ha on surrounding ungrazed native rangeland. There were no differences (P > .05) among wheatgrasses in standing crop of current year's growth during spring, summer, or fall. Crude protein concentrations did not differ (P > .05) among wheatgrasses with seasonal advance. However, all the wheatgrasses showed a consistent decline in nutritional quality from spring to summer to fall. All the wheatgrasses we studied will provide high-quality, spring (mid-April to mid-June) forage for livestock. During summer, use of native range is advantageous because it contains a high component of warm season grasses and forbs. Interseeding shrubs in wheatgrass seedings could reduce protein supplementation costs in winter.