Yield performance and land-use efficiency of barley and faba bean mixed cropping in Ethiopian highlands

Abstract

Mixed intercropping of barley ( Hordeum vulgare L.) with faba bean ( Vicia faba L.) was compared with sole cropping for three growing seasons (2001–2003) at Holetta Agricultural Research Centre, in the central highlands of Ethiopia. The treatments were sole barley (125 kg ha −1), sole faba bean (200 kg ha −1) and an additive series of 12.5, 25, 37.5, 50 and 62.5% of the sole seed rate of faba bean mixed with full barley seed rate. A randomised complete block design replicated four times was used. Mixed cropping and year effects were significant for seed and biomass yields of each crop species. Barley yield was reduced by mixed cropping only when the seed rate of faba bean exceeded 50 kg ha −1 or 25% of the sole seed rate. There was no mixed cropping by year interaction effect for barley grain yield but for faba bean seed yield. Total yield, barley yield equivalent, land equivalent ratio (LER) and system productivity index (SPI) of mixtures exceeded those of sole crops especially when faba bean seed rate in the mixture was increased to 75 kg ha −1 (37.5%) or more. The highest barley yield equivalent, SPI, crowding coefficient and LER were obtained when faba bean was mixed at a rate of 37.5% with full seed rate of barley. From this study, it is inferred that mixed intercropping of faba bean in normal barley culture at a density not less than 37.5% of the sole faba bean density may give better overall yield and income than sole culture of each crop species.