Soil fertility management at Dorebafano-2021

Common bean (Phaseolus vulgaris L.) Is an important grain legume in Ethiopia. However, the national average yield is very low due to a number of abiotic and biotic stresses, soil fertility depletion, fertilizer application without soil test, and poor crop response to fertilization. Crop specific and soil test based fertilizer recommendations are necessary for sustainable crop production. Therefore, a field experiment was conducted at Wulbareg district to study the effect of integrated use of Rhizobium inoculation, vermicompost, and phosphorus fertilizer on yield and yield components of common bean and on selected soil properties during the 2022 main cropping season. A factorial combination of three phosphorus rates (0, 20, 40 kg P ha-1), three vermicompost rates (0, 4, 8 ton ha-1) and 2 levels of Rhizobium inoculation were laid out in randomized complete block design (RCBD) with three replications. Analysis of baseline soil samples showed that the soil of the experimental area is loam in texture, very strongly acidic in reaction, low in organic carbon, low in total nitrogen, low in available P and high in CEC. The analysis of variance showed that the application of P, VC, Rh inoculation and their interaction significantly (p<0.05) increased most yield and yield parameters of the common bean compared to the control treatment. The highest grain yield (3487.65 kg ha-1) was recorded from 40 kg P ha-1and 4 t ha-1 VC followed by 40 kg P ha-1and 8 t ha-1 VC (3395.06 kg ha-1), whereas the lowest grain yield (2098.7 kg ha-1) was recorded from the control. Integrated application of biofertilizer, organic and mineral fertilizers showed a significant influence on BNF. The highest fixed nitrogen (54.42kg ha-1) and %Ndfa (52.42%) was obtained from the application of phosphorus 20 kg P ha-1, 8 t ha-1 vermicompost and rhizobia inoculation whereas the lowest was (16.12 kg ha-1) and (24.66%) from the control respectively. Most selected soil properties were influenced by the main effect of P, Rh, VC and by their interaction. Bulk density of soil, pH, Organic carbon, total nitrogen, phosphorus and CEC was increased from (1.3 kg cm-3) to (1.1kg cm-3), (5.38) to (5.45), (0.97%) to (2.91%), (0.08%) to (0.25%), (6.03mg kg-1) to (13.88mg kg-1) and (40cmol(+)kg-1) to (44.5 cmol(+)kg-1) respectively when compared to soil properties before planting. Soil moisture content was affected significantly by VC, PxVC, RhXVC and PXVCXRh which confirm VC effect on moisture content of the soil. Therefore, the result verified that using integrated phosphorus (40kgha-1), vermicompost (8tha-1) and rhizobium inoculation is recommended in the area of wulbareg district to improve the fertility of the soil and the productivity of the common bean.