Abstract:
Common bean (Phaseolus vulgaris L.) is an important legume crop with high food and
industrial use in Western Ethiopia. However, the productivity of the crop is extremely low,
which could be attributed to low soil fertility, little practice of fertilizer application by
farmers and soil acidity. Therefore, a field experiment was conducted at Nejo Agriculture
Polytechnic College in Western Ethiopia during the 2023 cropping season in order to
determine the optimum rate of NPS responses of Common bean, to determining the optimum
rate of VC responses of Common bean, to determine effect of NPS and VC on soil
physicochemical properties and to assess economic visibility of the Combination effect of NPS
fertilizers at Nejo western Ethiopia. Four NPS fertilizer rates (0, 50, 100, and 150 kg ha-1)
and four Vermicompost rates (0, 1.25, 2.5 and 3.75 tons ha-1) were used in the experiment.
The experiment was laid out randomized complete block design in a 4×4 factorial
arrangement with three replications,. The result showed that main effects of NPS and
Vermicompost fertilizer rates significantly affected all the parameters. The highest days to
50% flowering (50.33days), days to 90% physiological maturity (84.33 days), number of total
nodules (56.33) and number of effective nodule (50.83), were recorded from the combined
application of 150 kg NPS ha-1 and 3.75 t VC ha-1. while the highest number of primary
branches per plant (3.4), plant height (85.7 cm), leaf area per plant (3137 cm2), leaf area
index (5.38), number of seeds per pod (5.12), hundred seed weight (27.44 g), and dry
biomass (6894 kg/ha) were obtained from the application of 150 kg NPS and 3.75 t VC ha-1.
The NPS rate of 100 kg ha-1 with 2.5 t Vermicompost ha-1 resulted in higher values of grain
yield (2606 kg ha-1) and harvest index (50.93%). The results also showed that using 100 kg
ha-1 NPS fertilizer in combination with 2.5 t ha-1 Vermicompost produced the highest grain
yield. The application of 50 kg ha-1 NPS fertilizer with 3.75 t ha-1 Vermicompost resulted in
the highest marginal rate of return (604.83%) and the best net profit. Therefore, a combined
application of 50 kg NPS ha-1 fertilizer and 3.75 t ha-1 Vermicompost can be recommended
for the farming community in the study area. However, the study should be repeated for more
seasons and at different locations to come up with conclusive results.
