Phosphorus cycle is sedimentary cycle because it does not enter into atmosphere. It can be found on earth in water, soil and sediments. The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere and biosphere.

It involves following steps:

1.        Phosphorus is an important nutrient for plants and animals in the form of PO₄³. It is building block of certain parts of human and animal body such as bones and teeth.

2.      When animals and plant die, the phosphorus retrieves back to the soil and oceans in the form of PO₄³ ions by micro organisms.

3.      Some of phosphorus in the form of phosphate salts also comes into soil through weathering process of rocks.

4.      Phosphorus from the soil is absorbed by plants which convert it into organic phosphate animal absorb phosphorus by eating or plants eating animals.