BIOLOGICAL AND ECONOMIC ESTIMATION OF BENEFITS OF INTER-CROPPING VETCH IN SORGHUM FOR INTENSIFYING EXISTING PRODUCTION SYSTEMS IN GUMARA-MAKSEGNIT WATERSHED, NORTH GONDAR, ETHIOPIA

Abstract

Intercropping legume forages in cereal crops is a widely proposed strategy to improve land use efficiency, and maximize the economic value of the farming system, especially in developing countries with restricted resources. The current study was carried out during the successive rainy seasons of 2019 and 2020 in the Gumara-Maksegnit watershed, Gondar Zuria district, Ethiopia to evaluate the feasibility of forage legume inter-cropping in a food sorghum-based inter-cropping system. The experiment was laid down in a randomized complete block design with 3 replications. Local sorghum variety ‘Kucho’ and the vetch Vicia villosa were used for the experiment. Sole sorghum at 75 cm row spacing (T1); sorghum at 75 cm row spacing plus vetch with simultaneous planting (T2); sorghum at 75 cm row spacing plus vetch planted 2 weeks after sorghum (T3); sorghum at 75 cm row spacing plus vetch planted 3 weeks after sorghum (T4); sorghum at 150 cm row spacing plus vetch with simultaneous planting (T5); sorghum at 150 cm row spacing plus vetch planted 2 weeks after sorghum (T6); and sorghum at 150 cm row spacing plus vetch planted 3 weeks after sorghum (T7) were applied as study treatments, on plant height (cm), grain yield (t ha^-1), Stover yield (t ha^-1) and thousand seed weight(g) of sorghum, plant height (cm) and dry biomass yield (t ha^-1) of Vetch. In addition, an economic analysis was made for the feasibility of under-sowing vetch in sorghum crops.  At 75 cm row spacing sorghum was planted at 1 seed per hill and at 150 cm row spacing at 2 seeds per hill to maintain a constant population across treatments. Results revealed that the highest grain and Stover yields of sorghum were obtained from T1, T3, T4 and T7. Sorghum planted at 75 cm row spacing plus vetch with simultaneous planting (T2) produced the highest vetch dry matter yield during both years. Earlier vetch planting significantly depressed both grain and Stover yields of sorghum relative to a pure stand of sorghum. On the other hand, the earlier the vetch was planted the greater the dry matter yields of vetch produced. The economic assessment revealed that sowing sorghum at 75 cm row spacing and under-sowing of vetch at the same time was more profitable than pure sorghum with 15,550.00 ETB ha^-1 gross margins. With the ultimate acceptance of the technology sorghum in 75 cm row spacing plus Vetch with simultaneous planting (T2) was found economically profitable. Based on the results of this study it is suggested that to get higher economic return from a given area of land, nutritious and high-quality fodder and soil improvement through nitrogen fixation, farmers should adopt the practice of intercropping sorghum with forage legumes, preferably sorghum in 75 cm row spacing plus Vetch with simultaneous planting. The testing of this system on a field scale would either confirm or reject the hypothesis that it is more profitable than the conventional pure sorghum planting system. Soil analyses to determine possible increased soil N levels could demonstrate additional benefits. Feeding studies to show the benefits of feeding vetch hay to livestock in comparison with sorghum stover would confirm other potential benefits