How many types of fertilizers in the world?

There are primarily three types of fertilizers: organic, inorganic (or synthetic), and biofertilizers. Organic fertilizers are derived from natural sources like compost and manure, while inorganic fertilizers are chemically manufactured and provide specific nutrients. Biofertilizers contain living microorganisms that enhance nutrient availability in the soil. Each type serves different agricultural needs and can vary widely in composition and application.