By: Jermaine Loutin (Jose Marti Six Form Envi.)

The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movements of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

Importance of the Phosphorus cycle

Phosphorus is an essential nutrient for plants and animals in the form of ions PO4

3- and HPO42- .

It is a part of DNA-molecules and RNA-molecules, molecules that store energy (ATP and ADP) and of fats of cell membranes.

Phosphorus is also a building block of certain parts of the human and animal body, such as the bones and teeth.By: Jermaine Loutin (Jose Marti Six Form

Envi.)

Initially, phosphate weathers from rocks. The small losses in a terrestrial system caused by leaching through the action of rain are balanced in the gains from weathering rocks. In soil, phosphate is absorbed on clay surfaces and onganic matter particles and becomes incorporated

By: Jermaine Loutin (Jose Marti Six Form Envi.)

Herbivores obtain phosphorus by eating plants, and carnivores by eating herbivores. Herbivores and carnivores excrete phosphorus as a waste product in urine and feces. Phosphorus is released back to the soil when plants or animal matter decomposes and the cycle repeats.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

By: Jermaine Loutin (Jose Marti Six Form Envi.)

AN ECOSYSTEM VIEW OF THE PHOSPHORUS CYCLE

The ecosystem phase of the phosphorus cycle moves faster than the sediment phase. All organisms require phosphorus for synthesizing phospholipids, NADPH, ATP, nucleic acids, and other compounds. Plants absorb phosphorus very quickly, and then herbivores get phosphorus by eat plants.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

•Then carnivores get phosphorus by eating herbivores. Eventually both of these organisms will excrete phosphorus as a waste. This decomposition will release phosphorus into the soil. Plants absorb the phosphorus from the soil and they recycle it within the ecosystem.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

By: Jermaine Loutin (Jose Marti Six Form Envi.)

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.)

By: Jermaine Loutin (Jose Marti Six Form Envi.)

After millions of years, the After millions of years, the crustal plates rise from the crustal plates rise from the sea floor and expose the sea floor and expose the phosphates on land. After phosphates on land. After more time, weathering will more time, weathering will release them from rock and release them from rock and the cycle's geochemical phase the cycle's geochemical phase begins again. begins again.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

By: Jermaine Loutin (Jose Marti Six Form Envi.)

Human influences on the phosphate cycle come mainly from the introduction and use of commercial synthetic fertilizers. The phosphate is obtained through mining of certain deposits of calcium phosphate called apatite.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

• PLANTS MAY NOT BE ABLE TO UTILIZE ALL OF THE PHOSPHATE FERTILIZER APPLIED, AS A CONSEQUENCE, MUCH OF IT IS LOST FORM THE LAND THROUGH THE WATER RUN-OFF. THE PHOSPHATE IN THE WATER IS EVENTUALLY PRECIPITATED AS SEDIMENTS AT THE BOTTOM OF THE BODY OF WATER. IN CERTAIN LAKES AND PONDS THIS MAY BE REDISSOLVED AND RECYLED AS A PROBLEM NUTRIENT.

By: Je

rmain

e Lo

utin

(Jose

Marti S

ix

Form

Envi.)

•Other human sources of phosphate are in the out flows from municipal sewage treatment plants. Without an expensive tertiary treatment, the phosphate in sewage is not removed during various treatment operations. Again an extra amount of phosphate enters the water

By: Jermaine Loutin (Jose Marti Six Form

Envi.)

By: Jermaine Loutin (Jose Marti Six Form Envi.)

The phosphorus cycle differs from the nitrogen and carbon cycles because phosphorus is unable to achieve the gaseous state in the atmosphere. Phosphorus is mainly found in water, soil and sediments. In the atmosphere, phosphorus is found as fine dust particles.

By: Jermaine Loutin (Jose Marti Six Form Envi.)

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

By: Jermaine Loutin (Jose Marti Six Form Envi.)

QUESTIONS What is the phosphorus cycle? {Danique

Brooks} How is the phosphorus cycle different from the

other biogeochemical cycles? {Kemar Brown} Name two importance of phosphorus to plants

and/or animals. {Chevel Watson & Jeniel Thorpe}

Name the main way in which phosphorus is released ‘naturally’ in the environment. {Stacey- Ann Dunkley & Mitch Wright}

Name two ways humans help to release phosphorus in the environment {Alicea Scott & Kareen Mathews}

By: Jermaine Loutin (Jose Marti Six Form Envi.)