Evaluating the compatibility of highland sorghum {Sorghum Bicolor (L.) Moench} varieties for relay-intercropping with chickpea [Cicer Arietinum (L.)] at highland areas of west Hararghe, Ethiopia

Abstract

Relay-intercropping is a type of multiple cropping system that ensures the maximum production of component crops (sorghum and chickpea) through wise use of farmland resource. Nowadays, the two key challenges of developing countries including Ethiopia are the fast growing food demand and lower rate of food crop production. West Hararge highlands of study site is a potential area for production of sorghum and chickpea and sorghum is main food crop. Hence, farmers have been producing these crops since right now but its production is so low mainly due to farmland scarcity. The lower rate of crop production due to farmland scarcity could be tackled through adopting compatible sorghum-chickpea relay-intercropping system enables the farmer to produce two or more crops on the same plot of land in one production year. However, this practice is not well adopted at study area of the west Hararghe highlands. Therefore, field study was aimed at evaluating compatibility of highland sorghum varieties for relay-intercropping with chickpea for maximum productivity of sorghum and chickpea. Treatments were composed of one chickpea variety relay-intercropped with eight varieties of highland sorghum (Jiru, Dibaba, Adelle, Chiro, Chelenko, AL70, Local & ETS-2752) at physiological maturity of sorghum varieties in 1:2 row arrangements (1row Sorghum: 2 row chickpea) uniformly forming eight combinations along with two sole crops (sorghum and chickpea) as control. Hence, a total of ten treatments were arranged in a randomized complete block design (RCBD) with three replications. According to analysis of variance, treatments were significantly (p < 0.01) affected the plant height, days to 50 % flowering, days to physiological maturity, dry biomass yield, grain yield and thousand seed weight of sorghum, and highly significantly (p < 0.01) affected stand count, number of pods per plant and grain yield of chickpea, however, plant height, number of seeds per pod and hundred seed weight of chickpea were non-significantly (p > 0.05) affected by the treatments. The highest 4.21 tha -1 & 2.33 tha -1 grain yield of sorghum and chickpea respectively were recorded from relayintercropping 1row Jiru var. with 2 row Chickpea and sole chickpea respectively. With this result, the 13.78 % extra grain yield of sorghum was recorded due to relay-intercropping over sole-cropping. Thus, relay-intercropping of 2 row Jiru var. with 2row chickpea showed best performance in grain yield of sorghum. Moreover, the highest total land equivalent ratio of 1.93 was recorded from relay-intercropping 1 row Jiru var. with 2row Chickpea indicating yield advantage over sole-cropping system. In general, the result of this study confirmed that sorghum-chickpea relay-intercropping is best option to maximize the productivity of sorghum and chickpea. Therefore, since, the highest total land equivalent ratio was obtained from relay-intercropping1row Jiru var. with 2 row Chickpea for maximum productivity of component crops, then could be recommended for the study area of West Hararghe...