👉 Phosphorous is a chemical element that has the symbol P and atomic number 15. It is used as a fertilizer in agriculture, as it can be converted into organic matter through photosynthesis. Phosphorous is also important for many biological processes, including growth, reproduction, and energy production. In addition to its role as a fertilizer, phosphorous plays an important role in the Earth's atmosphere as a greenhouse gas that helps regulate the climate by trapping heat from the sun.