To grow and photosynthesize, plants need the sun, water and nutrients from the soil.
A plant absorbs these nutrients through the root system. Some nutrients are in unavailable forms, so the roots cannot absorb them. Microorganisms present in the soil can change these unavailable forms into nutrients the plant’s roots can absorb. The greatest concentration of beneficial microorganisms is found close to plant roots. This area is called the “Rhizosphere”. The microorganisms are called plant-growth promoting rhizobacteria or PGPRs. The microbes absorb carbon for energy and change it into carbon forms plant roots can use. This process also ties up the nutrients in the soil, so they are less likely to leach out with rainwater or manual watering. As the number of beneficial microorganisms increases the number of pathogens, or microbes which harm plants, diminish. They compete with each other for carbon, oxygen and space. Continuous introduction of beneficial microorganisms helps to maintain these protective levels in the soil and improves the nutrient uptake at the rhizosphere.