Forage Yield and Nutritive Values of Vetches Grown as a Sole and Intercropped with Desho Grass at Different Row Spacing in Western Oromia, Ethiopia

Legume forage, like vetches, is an important feed source for animals as a supplement to low-quality feeds. This study was conducted to evaluate the forage yield and nutritional values of vetches intercropped at various spacings of desho grass. The study was designed in a factorial arrangement with a randomized complete block design with three inter-row spaces (0.50 m, 0.75 m, and 1 m) and intercropping two vetches (Vicia sativa ICARDA 61509 and Vicia dasycarpa lana) and desho grass with three replications. Agronomic parameters, forage and seed yield, chemical analysis, and in vitro digestibility of vetch forage samples were determined. Results showed that significant differences (p<0.05) were observed for all measured agronomic parameters of vetches, except leaf length, due to spacing and interaction effects. Dry matter yield of vetch (DMY) was only affected by row spacing, while crude protein yield (CPY) was affected by row spacing and their interactions. Higher DMY (3.87 - 4.04 t/ha) and CPY (0.74 - 0.79 t/ha) were obtained from solely grown vetches as compared to intercropped vetches (2.26 - 2.42 t/ha and 0.417 - 0.423 t/ha), respectively. Forage yield significantly decreased as row spacing increased. Seed yield decreased as the row space increased, and the yield obtained from Vicia sativa ICARDA 61509 was higher (0.6 and 1.23 t/ha) than Vicia dasycarpa lana (0.41 and 0.82 t/ha) when either intercropped with desho grass or sown alone, respectively. The interaction of intercropping with spacing unaffected vetch's chemical composition. However, crude protein (CP) and acid detergent lignin of vetches were influenced by intercropping, whereas CP, neutral detergent fiber, and acid detergent fiber were affected by spacing (p<0.05). Intercropped Vicia dasycarpa gave higher in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility, and metabolizable energy than Vicia sativa, and IVDMD increased as row spacing increased from 0.5 to 1 m.