By Marilyn Dalen, Tubana, Brenda S.
LSU AgCenter
Phosphorus is one of the three primary nutrients commonly found in fertilizers along with nitrogen and potassium. Phosphorus occurs naturally in soil, but it is usually in forms unavailable for plant uptake. Plants require phosphorus to grow, which is why farmers have been feeding it to their crops for centuries. Proper management and application of phosphorus is critical because overloaded phosphorus in the soil can runoff into water supplies and become a major pollutant, and there has been a phosphorus fertilizer shortage due to depleted sources of phosphate rocks.