EFFECT OF INTERCROPPED FORAGE LEGUMES AND THEIR POPULATION WITH SORGHUM (Sorghum bicolor L.) ON THE PERFORMANCE AND PRODUCTIVITY OF COMPONENT CROPS IN EAST HARARGHE, ETHIOPIA

The shortage of arable land and shortage of livestock feed are major constraints in East Hararghe zone. Realizing the potential of intercropping to address this problem, a field experiment was conducted during 2020 crop season in East Hararghe, Ethiopia; To investigate the effect of intercropping forage legumes at different population with sorghum on the performance and productivity of component crops. Three forage legumes (vetch, lablab and cowpea) were intercropped at population of 25%, 50% and 75% with sorghum at recommended spacing of 75 cm x 20 cm along with the respective sole crop of sorghum (75 cm x 20cm) and forage legumes (40 cm x 10 cm) .The experiment was laid out in randomized complete block design in factorial arrangement in three replications. The results show that physiological maturity, leaf area, leaf area index, grain yield, harvest index of the intercropped sorghum were significantly affected by the main effect of forage legume,plant population of forage legumes,their interaction and cropping system. The longest days to flowering(84.22) sorghum/cowpea and physiological maturity (110.44) days of sorghum/lablab. Were recorded highest above ground dry biomass (11166.7 kg ha-1 ) of sorghum were obtained by sorghum-lablab intercropping.In sorghum /lablab intercropping, days to 50% flowering of forage legumes was significantly delayed (83.889) and followed by cowpea/sorghum intercropping (84.22). The sorghum leaf area and leaf area index were significantly affected by the main effect of forage legumes, their population and cropping system. The highest leaf area (232.0cm2 ) and leaf area index (1.711) were recorded in sorghum/lablab intercropping at 50% population. Leaf area (230.3 cm2 ) and leaf area index (1.533) of sorghum were higher in sole sorghum as compared to the intercropped sorghum. The highest grain yield of sorghum was obtained in lablab/sorghum intercropping at 50% plant population (3645 kg ha -1 ). The highest fresh (8244 kg ha-1 ) and dry (4110 kg ha-1 ) biomass of forage legumes were recorded when forage legume was intercropped at 75% plant population with lablab. The highest LER (2.500) was obtaining from sorghum intercropped with lablab and followed by sorghum intercropping with cowpea at 50% plant population, indicating advantage of intercropping over sole cropping. Based on this study, it can be tentatively concluded that lablab/sorghum intercropping at 50% plant population found to be appropriate combination for intercrop with sorghum.