Synergistic Application of Bacterial Consortium and Organic Amendments Improves the Growth and Seed Quality of Mash Bean (Vigna Mungo L.)

Low soil organic matter contents are among the most predominant reasons behind reduced soil health and decreased agricultural productivity. Sustainable agricultural approaches encourage minimal farmer’s dependence on chemical fertilizers and favor their supplementation with organic and biofertilizers to ensure smooth crop growth and sustained soil health. These organic amendments improve soil health by regulating various soil physicochemical and biological properties and thereby, control soil nutrient dynamics. Moreover, their integration with beneficial bacteria has also yielded significant outcomes in lieu of plant growth promotion and soil health improvement. Here, we performed a pot experiment to check the efficiency of different bacterial combinations alone and in combination with biochar and press mud (0, 0.25 and 0.50% w/w) for improving the yield and quality attributes of mash bean. Mash bean seeds were coated with freshly prepared inocula of three different combinations of rhizobia and PGPR strains. We found that inoculation with different bacterial consortia led to a significant increment in all the measured growth matrices. However, among them, combination (Bacillus subtilis + Bradyrhizobium japonicum) along with BC at 0.50% and PM at 0.25% caused maximum increase in SDW (124%), No. of pods per plant (360%), soil dehydrogenase (297%), alkaline phosphatase (149%), seed crude protein (119%), N (118%), P (127%), K (63%), niacin (68%), and thiamine (195%) contents as compared to their respective uninoculated controls. Pearson correlation heatmap revealed a strong positive correlation between various plant attributes and soil enzyme activities such as ALP (r = 0.69***) and ACP (r = 0.70***) levels. Furthermore, ALP was positively correlated with the plant yield (r = 0.66). We concluded that beneficial consortium (Bacillus subtilis + Bradyrhizobium japonicum) applied synergistically along with press mud and biochar can significantly improve the yield and seed quality of mash bean and at the same time, enhance the soil biological health as pragmatic by increased soil enzyme activities.