Effect of Vetch Varieties Intercropped with Maize on Forage and Maize Yield Performance in Different Agro-Ecologies of West Arsi and East Showa Zone of Oromia, Ethiopia

Abstract

The study was conducted in different sites representing lowland, midland and highland agro-ecologies with an objectives to identify the best compatible varieties of vetch intercropped with maize for dry matter (DM) yield, maize grain yield and other yield parameters of the mixture. Accordingly, three vetch varieties released from Sinana Research Center; Vicia sativa (Gebisa), Vicia vilosa (Lalisa) and Vicia narbonensis (Abdeta) were tested in pure stands and intercropped with maize. The DM yield recorded for all vetch varieties at all sites were significantly (p<0.05) differ among the tested treatments. From the pure stand vetches, higher (p < 0.05) DM yield were recorded for V. vilosa and V. sativa varieties at lowland and highland sites, while at midland sites V.vilosa vetch variety produced the higher DM yield as compared to other vetch varieties. The DM yield of intercropped treatments were comparable and not significantly (P>0.05) differ at low and highland sites. However at mid altitude sites, V. vilosa intercropped with maize treatment have shown better DM yield (2.61t/ha) performance probably due to its higher competition for moisture, space, light and nutrition among the crop plants. The higher (P <0.05) total DM yield were obtained from the intercropped treatments at all sites as compared to sole cropping treatments. However, the value of total DM yield were comparable and not significantly (P>0.05) differ among all the intercropped treatment at all sites. The result also showed that there was no significant ( p> 0.05) differences among the tested treatments in maize grain yield at all sites except at lowland where the vetch varieties have significantly (p<0.05) affected grain yield as compared to the yield of sole maize treatment. The reason for maize grain yield reduction at the lowland site could be due to competition of vetches for nutrient and the insufficient moisture availability during the trial period. The yield reduction of 21.5%, 3.09%, and 14.3% were calculated due to V. vilosa, V. sativa and V. narbonensis vetches intercropped with maize respectively at the lowland site. Hence, except V. vilosa, the other vetch varieties could be intercropped with maize at this lowland sites as additional feed resource for the livestock. Land equivalent ratio (LER) for total dry matter yield were not significantly (P>0.05) differ among the tested intercropped treatments. Highest (1.51) LER for total DM yield was observed in case of V. narbonensis intercropped with maize at highland site while, the least values were recorded for V. vilosa and V. sativa intercropped treatments at mid altitude sites. The mean value of LER for total seed were also greater than 1.0 at all sites indicate that intercropping vetch with maize was more advantageous than sole cropping. Generally, V.vilosa variety was performed best in DM yield as compared to that of other vetch varieties in high and midland sites and hence it can be recommended as best vetch variety for dry matter production in intercropping with maize at these sites. While, intercropping of V.vilosa with maize have resulted in significant maize grain reduction at the lowland site. Therefore, V. sativa is more appropriate for intercropping with maize as compared to the other vetch in the lowland site. On the other hand, the DM yield obtained from the vetch varieties intercropped in maize at all sites were small probably due to planting time and seeding ratio of the mixture crops. To get the optimum benefit from intercropping; seeding ratio and planting time need to be further evaluated and adjusted for different types of vetch species depending upon the purpose and growing conditions. Moreover, the best performing vetches (V. vilosa and V. sativa) in intercropping with maize have to be further evaluated at farmers condition and demonstrated to the small holder farmers so that to tackle the feed shortage of the study areas.

Keywords: Intercropping, vetch varieties, forage legumes, mixed cropping