Fertilizers are food for plants. Just as we need an adequate and consistent diet to grow and stay healthy, plants and crops have to get proper nutrition from the soil to thrive.
Plants require a balanced supply of nitrogen, phosphorus, potassium, and sulphur. As plants extract these nutrients from the soil during every growing season, they must be replenished through fertilizers, manure, and compost added to fields or gardens annually.
The advantage of using fertilizers is they can be applied with more control to match crop needs and protect the environment. They can also supplement manure or compost to ensure the soil gets an adequate supply of nutrients. Fertilizer Canada emphasizes the importance of managing and balancing the supply of nutrients to prevent both over and under fertilization.