2. Phosphorus Cycle and Content
• Introduction
• Phosphorus Cycle
• Phosphorus Cycle Steps
• Phosphate solubilizing microorganism
• Human aspects on Phosphorus Cycle
• Positive effect of Phosphorus Cycle
• Negative effect of Phosphorus Cycle
• Examples of Phosphorus Cycle
• Reference
2 12/12/2021 Add a footer
3. Introduction
3 12/12/2021 Add a footer
Phosphorus is a chemical element with symbol P and atomic number 15.
A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost
always present in its maximally oxidized state, as inorganic phosphate.
Phosphorus is essential for life.
As part of the phosphate group, it is a component of DNA, RNA, ATP (adenosine
triphosphate), and the phospholipids that form all cell membranes.
Elemental phosphorus was first isolated as white phosphorus in 1669.
5. Phosphorus Cycle
• “The phosphorus cycle is the movement of phosphorus from the
environment to organisms and then back to the environment.”
5 12/12/2021 Add a footer
• The phosphorus cycle may also be referred to as the mineral cycle or sedimentary
cycle.
• phosphorus is the scarcest and therefore the one most limiting in any given
ecological system.
• The atmosphere does not play a significant role in the movement of phosphorus,
because phosphorus and phosphorus-based compounds are usually solids at the
typical ranges of temperature and pressure found on Earth
• Unlike the other cycles, phosphorus cannot be found in air in the gaseous state
7. Phosphorus Cycle Steps
7 12/12/2021 Add a footer
• The mechanism of the phosphorus cycle is not as
clearly understood as other biogeochemical
cycles.
• However, it is known that the phosphorus cycle is
a slow process, consisting of the following steps
8. 8 12/12/2021 Add a footer
1.Weathering
2. Absorption by
plants
3.Absorption by
Animals
4.Return to the
Environment
through
Decomposition
9. 1.Weathering
9 12/12/2021 Add a footer
• The phosphate salts are broken down from the rocks
• These salts are washed away into the ground where they mix in the soil.
• Phosphorus is found in the rocks in abundance
• That is why the phosphorus cycle starts in the earth’s crust
10. 2. Absorption by plants
10 12/12/2021 Add a footer
• The phosphate salts dissolved in water are absorbed by the plants
• the amount of phosphorus present in the soil is very less
• That is why the farmers apply phosphate fertilizers on agricultural land
• The aquatic plants absorb inorganic phosphorus from lower layers of water bodies
• phosphate salts do not dissolve in water properly, they affect plant growth in an eco system.
11. 3. Absorption by animals
11 12/12/2021 Add a footer
• The animals absorb phosphorus from the plants or by consuming plant-eating animals
• The rate of the phosphorus cycle is faster in plants and animals when compared to rocks
12. 4. Return to the environment through decompose
12 12/12/2021 Add a footer
• When the plants and animals die they are decomposed by microorganisms During this
process, the organic form of phosphorus is converted into the inorganic form, which is
recycled to soil and water.
• Soil and water will end up in sediments and rocks, which will again release phosphorus by
weathering.
• Thus, the phosphorus cycle starts over
18. Human aspects on Phosphorus Cycle
• The phosphorus fertilizers increase the level of phosphorus in the soil
• Overuse of these fertilizers reduces the fertility of the soil and is also harmful to the
microorganisms present in the soil
• When these are washed away into the nearby water bodies, they are hazardous to
aquatic life.
• During the shipping of food from farms to cities, the amount of phosphorus that is
washed away in water causes eutrophication.
• This leads to the growth of algae.
• These form algal blooms or die, which is toxic to the aquatic ecosystem.
18 12/12/2021 Add a footer
21. Positive Effect of Phosphorus Cycle
• Phosphorus is an essential nutrient for animals and plants.
• Animals absorb phosphates by eating plants or plant-eating animals.
• a critical role in cell development
• Most protein-rich foods are a good source of phosphorus too, but some
non-protein foods also contain phosphorus.
21 12/12/2021 Add a footer
24. Negative Effect of Phosphorus Cycle
• there is a large quantity of phosphorus in the soil, much of it is in a form that isn’t
accessible to the plants.
• Adding more phosphorus through the use of fertilizers.
• it can pose a detrimental negative side effect on the environment.
• Extra phosphorus builds up in the soil and eventually runs off (along with nitrogen)
into our waters, harming marine animals.
24 12/12/2021 Add a footer
25. 25 12/12/2021 Add a footer
Phosphorus eutrophication on marine
ecosystem
27. 1. Lithosphere
• The largest phosphorus reservoir on the Earth is the minerals in the lithosphere.
• The initial source of phosphorus on Earth is obtained via chemical weathering and soil
formation processes.
• These compounds are either formed from volcanoes and earthquakes.
• phosphorus returns back to the land as the phosphorus-rich soil.
• These soil particles form layers of sediments underneath the water.
27 12/12/2021 Add a footer
28. 2. Biosphere
• Most of the phosphorus is not available to living beings .
• The biosphere, acts as a sink where the excess phosphorus can be stored.
• Living organisms take up phosphorus to form different biomolecules.
• The microorganisms found in the biosphere also play an essential role.
• they help in the solubilization of inorganic phosphorus.
• The biosphere acts as a middle man in the recycling of phosphorus back to the
lithosphere.
28 12/12/2021 Add a footer
30. 30 12/12/2021 Add a footer
• Microorganisms produce acids that form soluble phosphate from insoluble
phosphorus compounds.
• The phosphates are utilized by algae and terrestrial green plants, which in
turn pass into the bodies of animal consumers.
• Upon death and decay of organisms, phosphates are released for recycling.
