Microbial inoculants are gaining importance for attaining sustainable agricultural production systems. Nutrient supply capacity of soil is diminishing continuously owing to soil erosions, degradation, deposition of salts, undesirable elements and metals, water scarcity or excess and imbalanced nutrient supply system. Numerous complementary microbial inoculation combinations are contributing immensely in the management of plant nutrients by way of fixation, solubilization or transformation in soil. Thus, biological wastes and microbial inoculants are alternatives for nutrient demands to bridge future gaps in. A consortium of microorganisms provides enabling and congenial option to maintain their usable capacity for sufficient durations that heads to the positive impact on the microbial activity of soil for desired activities at the target sites. Increased application of agro-chemicals results in deleterious effect on biological system and dependence of future agriculture on these will lead to deterioration in soil health, threats of pollution of water bodies and cumulative effect of these is making production system highly vulnerable and unstable consequently leading to heavy load on the fiscal system. To ameliorate negative impacts, microorganisms are strongly emerging as alternatives for conserving productive capacity for sustainable productions and financial balance of economies. Microbial inoculants that have assumed definite and significant roles for their specificity and necessity and their use in various combinations have emerged as viable and sustainable options to maintain and even enrich the soil health. Since these microbial inoculants are used under varied farming situations and diverse climates with heterogeneous management skills, their efficacies under field conditions remain variable. Thus, it is never-ending process to identify solutions for constraints and application difficulties and further identify newer microbial inoculants for unexplored areas. Adequate timely and quality access of these inoculants to end users is equally important along with developing their skills to utilize these for witnessing desirable and visible impacts.
Keywords: Microbial inoculants; Plant nutrients; Quality control; Sustainable agriculture; Symbiotic organisms.