Phosphorus is a major constituent of biological membranes, nucleic acids and cellular energy transfer system(ATP) Animals need phosphorus to make shell, bones and teeth. Reservoir pool of phosphorus is the rock, which contain phosphorus in the form of phosphates.
During weathering of rock small amount of phosphates dissolved in soil solution and are absorbed by the roots of the plants. Herbivore and other animals obtain organic form of phosphorus from plants.
The waste product and dead organisms are decomposed by phosphate-solubilising bacteria releasing phosphorus.
How phosphorus cycle differs from carbon cycle?
There is no respiratory release of phosphorus into atmosphere. Atmospheric inputs of phosphorus through rainfall are much smaller. Gaseous exchange of phosphorus between organism and environment are negligible.