Influence of vermicompost, biofertilizer and NPS on soybean [(Glycine max (L.) Merrill] physiological seed quality, seed production and storage potentials

This study evaluated the effects of vermicompost, biofertilizer, and NPS fertilizer on the physiological seed quality, seed production, and storage potential of soybean [( Glycine max (L.) Merrill)]. A field experiment was carried out to determine the effect of different type of plant nutrient in sole and in combination on seed yield, quality and storeability of soybean. These nutrients was arranged in factorial experiment with three soybean varieties and laid out in randomized complete block design with three replications. The storage experiment was done using composite sample of soybean seed obtained from experiment treated by aforementioned plant nutrient and arranged in factorial experiment and laid out in CRD replicated four times for this experiment. Field experiments revealed that soybean varieties and fertilizer treatments significantly influenced growth, yield, and yield components. Belessa-95 showed superior performance for seed size (153.35 g TSW), pods per plant (33.10), and seed yield (1527.5 kg ha −1 ), whereas Gishama recorded the lowest values for most traits. Integrated organic and biofertilizer applications, particularly vermicompost and biofertilizer plus vermicompost, consistently produced higher seed yields (1842.3 kg ha −1 ) than chemical fertilizers and control plots. Laboratory and storage experiments demonstrated that soybean seed vigor, shoot growth, and germination were significantly affected by variety, fertilizer type, and storage period. Vermicompost, biofertilizer plus vermicompost treatments enhanced seedling performance, while prolonged storage (8 months) reduced seed quality. Correlation analysis indicated that standard germination was positively associated with root length, vigor indices, and shoot dry weight, whereas shoot length showed inverse relationships with seedling vigor traits. Economic analysis revealed that Belessa-95 treated by vermicompost provided the highest net benefit (15,460.54 ETB ha −1 ) and marginal rate of return (1088.13%), highlighting the profitability of organic fertilizer management. Overall, the findings suggest that combining improved soybean varieties with organic fertilizers, particularly vermicompost, can enhance yield, seed quality, storage potential, and economic returns, offering a sustainable strategy for soybean production under Ethiopian conditions.