ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 74 Number 3
Dry matter yield and forage quality of perennial grasses interseeded with annual legumes in the tropical highlands of Ethiopia
The objective of this study was to determine if seeding annual legumes with perennial grasses would improve yield and forage quality of mixtures during the seeding year. Two C4 grasses, rhodesgrass (Chloris gayana Kunth) and kleingrass (Panicum coloratum L.), and a C3 grass, hardinggrass (Phalaris aquatica L), were sown in monoculture or in mixture with three annual legumes in a black clay soil (vertisol). The legumes were quartin clover (Trifolium quartinianum A. Rich.) and rueppell clover (T. rueppellianum Fres.), which are indigenous to the highlands of Ethiopia, and woolypod vetch (Vicia villosa subsp. dasycarpa Roth) which is an introduced species. Grass-legume mixtures accumulated more dry matter (DM), crude protein (CP), and in vitro digestible dry matter (IVDDM) than grass monocultures. The best grass-legume mixtures were hardinggrass- and kleingrass-woolypod vetch. Average DM yield of C4 grasslegume mixtures was increased by 70%, concentrations of CP by 32%, and IVDDM by 7% compared to C4 monoculture. In the C3 grass-legume mixture, average DM increased by 25% and CP concentrations by 15%, but there was no improvement in IVDDM when compared to C3 monoculture. Woolypod vetch increased yield and CP concentrations of mixtures more than clovers, but, clovers improved IVDDM of mixtures more than woolypod vetch.
Keywords: Forage quality; Annual legumes; Perennial grass; Tropical highlands; Ethiopia