Bio’ means ‘life’. Therefore, by definition biofertilizers are living organisms that enrich the nutrient quality of the soil. It refers to the use of microbes instead of chemicals to enhance the nutrition of the soil. As a result, it is also less harmful and does not cause pollution.This is what makes them so important to organic farming because they are completely environment-friendly. Let’s take a look at the different microbes that are used as biofertilizers. You may have already studied the nitrogen-fixing nodules on the roots of legumes. This a great example of biofertilizers. The nodules are formed by the association of the bacterium ‘Rhizobium’ with the roots of these plants. This association is beneficial and is, therefore, called ‘symbiotic’.