Microorganisms help break down organic matter, they release essential nutrients and carbon dioxide into the soil, fix nitrogen and help transform nutrients into mineral forms that plants can use through a process called mineralization and nitrogen fixing bacteria improve soil fertility. Soil microorganisms alter the waste constituents through organic matter decomposition, inorganic transformations, and nutrient assimilation. These processes are largely restricted to the upper meter of soil. The ability of soil microorganisms to decompose organic matter is a function of their population complexity. Beneficial microbes in soil are known to enhance nutrient availability to plants, allowing for an increase in plant growth and productivity. Microorganisms have the potential to improve plant growth under abiotic stress conditions by promoting the production of low-molecular-weight osmolytes, such as glycinebetaine, proline, and other amino acids, mineral phosphate solubilization, nitrogen fixation, organic acids, and producing key enzymes. These microbes regulate nutrient cycling, regulation of dynamic of soil organic matter, and enhance efficiency of nutrient acquisition. The symbionts of microbes enhance the efficiency of nutrient acquisition of nutrient and water by plants. Beneficial microbes in soil are known to enhance nutrient availability to plants, allowing for an increase in plant growth and productivity. Soil micro-organisms are of great importance for plant nutrition as they interact directly in the biogeochemical cycles of the nutrients. The roots of most plants are infected with mycorrhizae, fungi that form a network of mycelia or threads on the roots and extend the surface area of the roots. Soil microorganisms (bacteria and fungi) are responsible for biomass decomposition, biogenic element circulation, which makes nutrients available to plants, biodegradation of impurities, and maintenance of soil structure.

Soil microbes play a vital role in the sustained growth of plants. They decompose and recycling nutrients bound in organic materials. They help access minerals in rocks large and small and they can even refine nitrogen from the air into a useful form for plants. Microorganisms like bacteria and fungi, act as decomposers as they break down the dead and decaying organisms into simpler nutrients that mix with the soil. These nutrients are absorbed by plants during photosynthesis. Microorganisms increase the source of nitrogen in the soil, or they can supply it directly to the plant, as they have the ability to take and set nitrogen from the atmosphere. Microorganisms, there is an increase in the bioavailability of phosphorus in the soil. Microorganisms play an important role in the nutrient cycle. Some bacteria (Plant Growth Promoting 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. 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. Microorganisms have the potential to improve plant growth under abiotic stress conditions by promoting the production of low-molecular-weight osmolytes, such as glycinebetaine, proline, and other amino acids, mineral phosphate solubilization, nitrogen fixation, organic acids, and producing key enzymes. Both plants and microorganisms obtain their nutrients from soil and change soil properties by organic litter deposition and metabolic activities, respectively. Microorganisms have a range of direct effects on plants through, e.g., manipulation of hormone signaling and protection against pathogens.