Effects of tillage depths and legumes integration on soil properties and maize ( <i>Zea Mays L.</i> ) productivity in Northwest Ethiopia

Abstract Intensive tillage and mono-cropping practices are among the major causes of soil degradation, low crop productivity and food insecurity in Sub-Saharan Africa. Information on optimum tillage depths and best maize-legumes intercropping for improving soil properties and crop yield under irrigation system is lacking. Hence, we conducted field experiment over two cropping years to examine the impact of different tillage depths and maize-legumes intercropping on soil properties and maize productivity in northwest Ethiopia. The treatments were combinations of three levels of tillage depths (zero, conventional, and deep tillage) and four levels of maize-legumes intercropping (maize + soybean ( Glycine max ), maize + haricot bean ( Phaseolus vulgaris) , maize + vetch ( Vicia faba ) and sole maize as a control), arranged in a randomized complete block design with three replications. Both the soil and crop data were subjected to analysis of variance using statistical analysis system software. The results showed that zero tillage depth and maize-soya bean intercropping in combination provided the highest mean soil pH (5.37), organic carbon (2.51%), total N (0.23%), available P (7.27 mg kg −1 ) and CEC (29.18 cmol (+) kg −1 ). Besides, the maximum mean dry biomass (17.52 tons ha −1 ), grain yield (7.73 tons ha −1 ), thousand-grain weight (416) and harvest index (44%) were achieved from deep tillage combined with maize-soya bean intercropping. In conclusion, maize-legumes intercropping under deep tillage can be a promising practice to improve nutrient availability and crop yield. However, further long-term research needs to be conducted in varied combinations of tillage depths and maize-legumes intercropping strategies in different agroecology.