THE PHOSPHORUS

CYCLE

WHAT IS THE WHAT IS THE PHOSPHORUS PHOSPHORUS

CYCLE?CYCLE? The phosphorus The phosphorus

cycle, is the cycle, is the circulation of circulation of phosphorous among phosphorous among the rocks, soils, the rocks, soils, water, and plants and water, and plants and animals of the earth. animals of the earth. Human beings and all Human beings and all other organisms must other organisms must have phosphorus to have phosphorus to live. In nature, most live. In nature, most phosphorus occurs in phosphorus occurs in phosphate rock, phosphate rock, which contains which contains phosphate ions phosphate ions combined with combined with calcium, magnesium, calcium, magnesium, chlorine, and fluorine. chlorine, and fluorine.

It cannot be found in air It cannot be found in air in the gaseous . This is in the gaseous . This is because phosphorous is because phosphorous is usually liquid at normal usually liquid at normal temperatures pressures. temperatures pressures.

This cycle is the slowest This cycle is the slowest of the matter cycles. of the matter cycles.

Phosphorus is most Phosphorus is most commonly found in rock commonly found in rock formations and ocean formations and ocean sediments as phosphate sediments as phosphate salts. Phosphates are salts. Phosphates are also limiting factors for also limiting factors for plant-growth in marine plant-growth in marine ecosystems, because ecosystems, because they are not very water-they are not very water-solublesoluble. .

THE PROCESS OF THE PROCESS OF THE THE

PHOSPHOROUS PHOSPHOROUS CYCLECYCLE The cycle basically starts The cycle basically starts

out in the earth’s soil. The out in the earth’s soil. The soil contains phosphate soil contains phosphate and when something grows and when something grows out of the soil it should out of the soil it should have phosphate as well. have phosphate as well.

When the plants grow When the plants grow they are consumed by they are consumed by herbivore and omnivore herbivore and omnivore animalsanimals

The animal’s waste or the The animal’s waste or the animal’s body when it dies animal’s body when it dies becomes detritus. becomes detritus.

Detritus is non-living Detritus is non-living organic material. When organic material. When the detritus goes deep the detritus goes deep into the soil, detritivores into the soil, detritivores in the soil decompose and in the soil decompose and become the soil’s become the soil’s phosphate and the cycle phosphate and the cycle repeats.repeats.

Another example of the Another example of the phosphorus cycle is when phosphorus cycle is when rocks are created. rocks are created.

The phosphate in the soil The phosphate in the soil moves on and transfers its moves on and transfers its phosphate to the rocks phosphate to the rocks underwater. When the underwater. When the uplifting of the rocks uplifting of the rocks occurs it takes the occurs it takes the phosphate along with it. phosphate along with it. After that the weathering After that the weathering of rocks occur and the of rocks occur and the rocks begin to break down rocks begin to break down into the soil and the into the soil and the phosphate in the rocks phosphate in the rocks ends up in the soil again ends up in the soil again and the cycle repeats. and the cycle repeats.

Uplifting of rocks

Weathering of rock

Runoff

Phosphates in rock

Phosphates in soil

(inorganic)

Phosphates in

solution

Precipitated (solid)

phosphates

RockDecomposition

Phosphates in

organic compound

s PlantsAnimals

Detritus

Detritivores Detritivores in soilin soil

All these examples of phosphates are inorganic All these examples of phosphates are inorganic (white boxes). However, the Phosphorus Cycle is also (white boxes). However, the Phosphorus Cycle is also organic (yellow boxes). organic (yellow boxes).

Not all phosphates in the runoff make it to the water; Not all phosphates in the runoff make it to the water; others sink into the soil. These inorganic phosphates others sink into the soil. These inorganic phosphates are transformed into organic ones by plants, which are are transformed into organic ones by plants, which are in turn eaten by animals. in turn eaten by animals.

The dead animals, retain their internal phosphorus The dead animals, retain their internal phosphorus stores and detritivores (scavengers which feed on stores and detritivores (scavengers which feed on dead plants and animals or their waste) change the dead plants and animals or their waste) change the organic phosphates back to inorganic ones. organic phosphates back to inorganic ones.

HOW DO HOW DO HUMANS HUMANS

INTERFERE WITH INTERFERE WITH THE THE

PHOSPHORUS PHOSPHORUS CYCLE?CYCLE?

Cutting and burning Cutting and burning of tropical rain of tropical rain forests affects the forests affects the phosphorus cycle. As phosphorus cycle. As the forest is cut the forest is cut and/or burned, and/or burned, nutrients originally nutrients originally stored in plants and stored in plants and rocks are quickly rocks are quickly washed away by washed away by heavy rains, causing heavy rains, causing the land to become the land to become unproductive.unproductive.

Agricultural runoff provides Agricultural runoff provides much of the phosphate much of the phosphate found in waterways. Crops found in waterways. Crops often cannot absorb all of often cannot absorb all of the fertilizer in the soils, the fertilizer in the soils, causing excess fertilizer causing excess fertilizer runoff and increasing runoff and increasing phosphate levels in rivers phosphate levels in rivers and other bodies of water. and other bodies of water. The phosphate in the water The phosphate in the water is eventually precipitated is eventually precipitated as sediments at the bottom as sediments at the bottom of the body of water. In of the body of water. In certain lakes and ponds certain lakes and ponds this may be re-dissolved this may be re-dissolved and recycled as a problem and recycled as a problem nutrient.nutrient.

Animal wastes or manure Animal wastes or manure may also be applied to the may also be applied to the land as fertilizer. If land as fertilizer. If misapplied on frozen misapplied on frozen ground during the winter, ground during the winter, much of it may lost as run-much of it may lost as run-off during the spring thaw. off during the spring thaw. In certain area very large In certain area very large feed lots of animals, may feed lots of animals, may result in excessive run-off result in excessive run-off of phosphate and nitrate of phosphate and nitrate into streams.into streams.

CRAP

A major problem A major problem with the use of phosphorus in fertilizers is the process of the use of phosphorus in fertilizers is the process of artificial eutrophication. Eutrophication is a large increase in the primary artificial eutrophication. Eutrophication is a large increase in the primary productivity of a lake. Eutrophication can be harmful to the natural balance productivity of a lake. Eutrophication can be harmful to the natural balance of a lake and result in massive death of fish and other animals as dissolved of a lake and result in massive death of fish and other animals as dissolved oxygen levels are depleted from the water.oxygen levels are depleted from the water.

Another human cause of Another human cause of artificial eutrophication is run-artificial eutrophication is run-off from mines. Mining in areas off from mines. Mining in areas where rock is rich in where rock is rich in phosphorus minerals can create phosphorus minerals can create dust that is blown by wind into dust that is blown by wind into nearby water systems.nearby water systems.

Thank you for your attention

we hope you enjoyed our presentation