Forage Yield and Quality of Dryland Grasses and Legumes

Abstract

A 7-year study was conducted on forage yield, digestibility, and crude protein of 7 species of grass, 3 cultivars of alfalfa, and cicer milkvetch at Sidney, Mont., from 1975 through 1981. Forage quality was inversely proportional with forage yield. Crude protein concentration of legumes and grasses decreased 0.8 and 1.25 percentage units, respectively, while dry matter digestibility decreased 1.5 to 2.3 percentage units per every 1,000 kg/ha increase in forage yield. Meadow bromegrass and reed canarygrass produced the least forage from the second through seventh years of the study. Neither forage yield nor quality differed among the 3 creeping-rooted alfalfas: 'Rambler', 'Drylander', and 'Orenberg'. Russian wildrye, Altai wildrye, and green needlegrass produced the most forage during the 1980 drought, and the alfalfas, pubescent wheatgrass, and meadow bromegrass produced the least. Cicer milkvetch and reed canarygrass died during the 1980 drought. Forage digestibility of the alfalfas was 5 to 6 percentage units higher than that of the grasses, and the alfalfas also produced more digestible forage per unit of land. The crude protein concentration of alfalfas was almost twice that in grasses, and alfalfa produced almost twice as much crude protein per unit of land (kg/ha).