Phosphorus cycle

The phosphorus cycle is mainly a sedimentary cycle. Unlike carbon and nitrogen, it has no major gaseous atmospheric phase under ordinary natural conditions.

Major processes

Weathering releases phosphate from rocks.
Plants absorb phosphate from soil or water.
Animals obtain phosphorus through food.
Decomposition returns phosphorus to soil and water.
Runoff carries phosphorus into aquatic ecosystems.
Sedimentation stores phosphorus in aquatic sediments over long periods.

UPSC relevance: Excess phosphorus from fertilisers, sewage and detergents can contribute to eutrophication in lakes and other water bodies.