Sulfur Cycle Definition and Meaning
What is Sulfur Cycle?
The sulfur cycle refers to the biogeochemical cycle by which this chemical element can be found in nature in its various forms, such as sulfate.
The sulfur cycle is considered one of the most complex chemical cycles in nature since in its journey through different ecosystems, sulfur experiences different oxidation states (this occurs when the chemical component combines with oxygen).
Sulfur, for its part, is a chemical element, not metal and the tenth most abundant in the earth’s crust, it is of great importance and is identified with the symbol S. It is characterized by being pale yellow in color and having an aroma that is quite unpleasant.
Also, sulfur is a nutrient of great importance in nature , especially for plants and animals. It can be found in soil or water, forming sulfates, or mixed with other elements.
Sulfur cycle process
Below is how the sulfur cycle develops:
- In principle, plants absorb sulfur through the roots, which is found in the earth’s crust or in water in the form of sulfate and makes up the salts or nutrients necessary to carry out their vital functions.
- Through this process, plants reduce sulfates to sulfides.
- Once in plants and vegetables, sulfur passes into the organism of herbivorous animals when they feed.
- Carnivorous animals then feed on herbivorous animals, which is why sulfur continues its cycle and contributes its nutrients to these consumers.
- When carnivorous animals die, their bodies are left in the ground, and decomposing organisms (bacteria and fungi) convert their animal remains back to sulfate as they disintegrate them and reduce them to organic particles.
- The sulfur present in the amino acids of the carcasses of the animals passes to the soil, which is later transformed into hydrogen sulphide thanks to the bacteria and, in this way, the soil is enriched and nourished again.
- In this process the sulfur is oxidized to produce the sulfate that will again be absorbed by the plants through their roots. In this way the cycle starts again.
Sulfur also reaches the soil through the faeces of animals, after decomposition.
Likewise, sulfur reaches the atmosphere as a gaseous compound such as sulfur dioxide and hydrogen sulfide, gases that are produced by volcanoes or fires and by the decomposition of organic matter generated by bacteria, both in the soil and in water.
In this case, when the hydrogen sulfide is in contact with the oxygen, it oxidizes, in this way the sulfate is generated, which then falls into the soil and water through the rains.
Conversely, sulfur dioxide can be absorbed by plants directly from the atmosphere.