Effect of spatial arrangement of faba bean variety intercropping with maize on yield and yield components of the crops

Efficient maize-faba bean intercropping system for optimum grain yield and productivity is needed in order to use the limited land and to enhance food security of the smallholder farmers. A field experiment was conducted at Haramaya, eastern Ethiopia during the 2018 and 2019 main cropping seasons to determine the effect of variety and spatial arrangement on a maize-faba bean intercropping system on yield components and yields of the component crops and the productivity of the system. The treatments consisted of the recommended 100% plant populations of maize (Baate) variety intercropped with 50% of the recommended density of four faba bean varieties (Yeferenji Baqela, Yehabesha Baqela, Batte and Gachena). The component crops were sown at three levels of spatial arrangements (1:1 1:2 and 2:2), whereas sole maize and the four faba beans were sole-planted. The treatments were laid out as a randomized complete block design with three replications in factorial approach. The results revealed that cropping season affected all the maize variables-cropped. Sole-cropped maize gave the higher grain yield (5.91 t ha(−1)) compared to intercropping system. Maize intercropped with 2:2 spatial arrangements gave the highest grain yield (5.37 t ha(−1)). Sole-cropped faba bean gave higher seed yield (2.04 t ha(−1)) than intercropped faba bean. The 1:1 spatial arrangement was superior in number of pods per plant (5.27), aboveground dry biomass (3.81 t ha(−1)), and seed yield (0.86 t ha(−1)) to the other spatial arrangements. Variety Gachena was superior to the other varieties in number of pods per plant (5.49), above ground dry biomass (3.77 t ha(−1)), seed yield (0.88 t ha(−1)). Land equivalent ratio (LER) was unaffected by variety differences; however, a 26.8% yield advantage was achieved at 1:1 spatial arrangement in which the highest LER (1.268) value was obtained. The highest gross monetary value (GMV) (96,308 ETB ha(−1)), maize equivalent yield (MEY) (6420.53 kg ha(−1)) and monetary advantage index (MAI) (17,506) was obtained from Gachena variety. A 1:1 spatial arrangement gave the maximum GMV (94,162 ETB ha(−1)), MEY (6277.49 kg ha(−1)) and MAI (18,761). Therefore, it is concluded that intercropping of Gachena variety in a 1:1 spatial arrangement with maize resulted in the highest productivity and economic advantage for the farmers of the study area.