Forage Yield, Botanical Composition and Adaptation of Some Forage Grasses and Legumes in Mono and Dual Cultures (Binary Combinations)

Forage species in mixtures are extensively grown worldwide nowadays, particularly as a step towards sustainable agriculture, however, information on this topic is scanty in our country. Thus a 2-year (2001-2003) field experiment was conducted to determine the forage yield, botanical composition, as well as competition of some forage grasses and legumes as mono and dual cultures combinations at Kushkak Agricultural Experiment Center, Shiraz University. The treatments were alfalfa (Medicago sativa L.), red clover (Trofolium pratense L.), orchardgrass (Dactylis glomerata L.), smooth bromegrass (Bromus inemis L.), and tall fescue (Festuca arundiacea Screb.) as monoculture and forage legumes along with grasses as dual cultures. Results showed that alfalfa monoculture and its dual culture with grasses had the highest total dry matter yields with significant differences as compared with red clover and its binary combinations. The forage yields were significantly higher during the 2nd than the 1st year. The highest total dry matter yield of alfalfa together with its binary combinations belonged to alfalfa-tall fescue and alfalfa-smooth bromegrass combinations. The competition of red clover with grasses was less pronounced than that of alfalfa. Orchardgrass had a lower competitive ability in binary combinations in both years, unlikely being able to compete with alfalfa; however, it produced a higher proportion of forage yield with red clover during the 2nd year. Alfalfa was a dominant species in alfalfa-smooth bromegrass combination and smooth bromegrass was a dominant species in red clover- smooth bromegrass combination. Overall, alfalfa-smooth bromograss and alfalfa-tall fescue binary combinations produced higher forage total dry matter in either one of the experimental years and it seems that they can endure a longer endurance in the region.