Healthy soil is teaming with bacteria, fungi, protozoa, nematodes, and many other micro and macro-organisms, making up the soil microbiome. Those organisms work together, living - dying, eating - being eaten, in cooperation with plants and the roots that supply many of the nutrients microorganisms need to thrive. Microbes make nutrients available to plants from the rhizosphere and ultimately help in their mobilization in the plant system. Nitrogen, phosphorus and potassium are the key elements involved in plant growth and development. The microbes lose their cell walls, become trapped in plant cells, and are hit with reactive oxygen. The reactive oxygen breaks down some of the microbe cells, effectively extracting nutrients from them. Surviving microbes spur the formation of root hairs on roots. Within food plant cropping systems, microorganisms provide vital functions and ecosystem services, such as biological pest and disease control, promotion of plant growth and crop quality, and biodegradation of organic matter and pollutants. Microorganisms play an important role in the nutrient cycle. Some bacteria secrete phytochemicals and organic acids that are helpful in the growth and development of plants. Microorganisms help maintain soil pH but balance nutrients and minerals. Soil microorganisms are a major component of the natural fertility of soils. They can promote plant growth, increase crop productivity and contribute significantly to the mineral nutrition of crop plants.

@ Sudip, you may use microbes for nitrogen-fixation, phosphorus solubilization and mobilization, suppression of pests and pathogens, improvement of plant stress, and decomposition that leads to soil aggregation. Microbial enzymes can be used for nano-nutrient production and enhancing polysaccharide production in the soil resulted more soil aggregation, moisture retention and soil carbon build up .

I agree with Dr J. C. Tarafdar that microbes contribute to soil formation through nutrient cycling and organic matter production. Microbial products are critical to soil aggregation, improved soil structure making soil more habitable for plants. Soils characterized by active microbes and close interactions between fauna and plants bolster efficient nutrient cycling, pathogen resistance and overall crop health, and enhance long-term ecosystem stability given the future global change conditions. Microbes make nutrients available to plants from the rhizosphere and ultimately help in their mobilization in the plant system. Nitrogen, phosphorus and potassium are the key elements involved in plant growth and development. Due to their close proximity to plant roots, soil microbes significantly affect soil and crop health. Some of the activities they perform include nitrogen-fixation, phosphorus solubilization, suppression of pests and pathogens, improvement of plant stress, and decomposition that leads to soil aggregation. Within food plant cropping systems, microorganisms provide vital functions and ecosystem services, such as biological pest and disease control, promotion of plant growth and crop quality, and biodegradation of organic matter and pollutants.