Field Evaluation of Five Grasses Grown on a Saline Soil

Abstract

Russian wildrye (Psathyrostachys juncea), Altai wildrye (Leymus angustus), creeping foxtail (Alopecurus arundinaceus), and 2 forms of a bluebunch wheatgrass (Pseuduroegneria spicata) × quackgrass (Elytrigia repens) hybrid (RS-1 and RS-2) were evaluated in 1983 and 1984 for their suitability as forage for beef cattle. Hybrid selections produced 5,554 kg/ha of forage and their yields in 1983 were significantly more than those from the 2 wildryes and creeping foxtail that averaged 2,810 and 4,292 kg/ha, respectively. In 1984, there was not a significant difference among yields for the 5 grasses, but there was a significant increase in yield from 1983 for the 2 wildryes and creeping foxtail. Percent crude protein averaged 16% in the wildryes and 12.5% in the 2 hybrids and creeping foxtail in 1983. However, percent phosphorus averaged .40% in the creeping foxtail and .30% in the hybrids. In 1984, percent crude protein and phosphorus for all 5 grasses were lower than in 1983, but trends were similar. All 5 grasses exceeded the NRC crude protein and phosphorous requirement for a 500-kg lactating cow in 1983. In 1984, only the creeping foxtail and RS-1 hybrid exceeded the phosphorous requirement. In vitro organic matter digestibility averaged 64% in the ryegrasses and 54% in the hybrids for both years. In 1983, all 5 grasses exceeded the metabolizable energy requirement of a lactating 500-kg cow. Based on calculated nutritional index, Russian wildrye and Altai wildrye ranked 1 and 2 with the creeping foxtail and RS-2 hybrid ranking 4 and 5, respectively, in 1983. In 1984, Russian wildrye and the creeping foxtail ranked 1 and 2, and the RS-1 hybrid and RS-2 hybrid ranked 4 and 5.