This document provides an overview of biofertilizers, including their types, application methods, advantages, and disadvantages. It describes various nitrogen-fixing biofertilizers like Rhizobium, Azotobacter, Blue-Green Algae, and their roles in soil fertility. Application methods for biofertilizers include seed treatment and soil application. Biofertilizers offer benefits such as atmospheric nitrogen fixation, increased nutrient availability, and plant growth stimulation, while posing minimal environmental damage. However, their effects may be specific to certain plants and soils, and they do not provide quick crop responses. Skill is required in biofertilizer production and application.