Phosphorus Cycle
The phosphorus cycle is the movement of phosphorus from the
environment to organisms and then back to the environment.
Phosphorus
 Mineral cycle
 Unlike the other cycles,
 phosphorus cannot be found
 in air in the gaseous state.
 Phosphorus is mainly found in
 water, soil, and rock.
Importance of Phosphorus
Organisms need phosphorus for biological processes. It is a major component of
DNA/RNA/ATP (important for energy transfer) as well as phospholipids that form all cell
membranes.
Phosphorus Cycle
 The phosphorus cycle is the SLOWEST cycle.
 Phosphorus is most commonly found in rock formations
and ocean sediments as phosphate salts.
 Phosphate salts that are released from rocks through
weathering usually dissolve in soil water and will be
absorbed by plants.
PHOSPHORUS CYCLE
 The phosphorus cycle occurs when
phosphorus moves from land to sediments in
the seas and then back to land again. The main
storage for phosphorus is in the earths crust.
On land phosphorus is usually found in the
form of phosphates
By: Jermaine Loutin (Jose Marti Six Form Envi.)
Phosphorus
 Phosphorus is a vital nutrient necessary for plants and
animals in the form of PO43- and HPO42-.
 Phosphorus is the building block of important parts of the
body such as bones and teeth.
 About 80% of the world’s phosphorus is used in fertilizers
and soft drinks.
 Phosphorus does not entre the atmosphere it stays in rocks
and soil minerals.
Phosphorus
 Unlike other cycles of matter compounds, phosphorus
cannot be found in atmosphere as a gas.
 It usually cycles through water, soil, and sediments.
Phosphorus Cycle
 Animals absorb phosphates by eating plants or plant-
eating animals.
 When animals and plants die, phosphates will return to
the soils or oceans again during decomposition.
 After that, phosphorus will end up in sediments or rock
formations again, remaining there for millions of years.
Eventually, phosphorus is released again through
weathering and the cycle starts over.
Phosphorus Cycle
By: Jermaine Loutin (Jose Marti Six Form Envi.)
Human Impacts
on the Phosphorus Cycle
 Like nitrogen, increased use of fertilizers increases
phosphorus runoff into our waterways and contributes to
Eutrophication and Algal bloom.
Human impacts on Cycle
 From the 1940’s trough 1900’s, phosphates used in laundry
detergents caused leached phosphorus emitions into streams,
rivers, and lakes.
 Fertilizers containing phosphorus lead to phosphates in water
(excess)
 In comparison to nitrogen and carbon, the rate at which phosphate
salts are released is extremely slow. Phosphorus can remain in rocks
or sediments for millions of years.
 Another human cause of artificial eutrophication is run-off from
mines. Mining in areas where rock is rich in phosphorus minerals can
create dust that is blown by wind into nearby water systems.
QUESTIONS
 What is the phosphorus cycle?
 How is the phosphorus cycle different from the other
biogeochemical cycles?
 Name two importance of phosphorus to plants and/or
animals.
 Name the main way in which phosphorus is released
‘naturally’ in the environment.
 Name two ways humans help to release phosphorus in the
environment
By: Jermaine Loutin (Jose Marti Six Form Envi.)