Phosphorus enters the soil after it is deposited on top of it by rain or snow. There are two different types of phosphorus that end up in the soil- organic phosphorus and inorganic phosphorus. Organic phosphorus is found in decomposing organic matter like animal excrement, which make up a small percentage of total phosphorus found in soils. Inorganic phosphorous can be found in rocks, minerals, volcanic ash, and other substances that make up the earth’s crust.
After entering the soil, both organic and inorganic forms of phosphorus are converted to soluble phosphate forms which are then taken up by plants through their roots to produce energy for themselves.