Atmospheric Cycles- Carbon, Oxygen and Nitrogen Cycle


The cycle of main gases found in the atmosphere is given below:-

—Carbon cycle

—Oxygen cycle

—Carbon dioxide cycle

 

[1] Carbon Cycle

The element of carbon is present in the atmosphere in the form of carbon dioxide.

The source of carbon for all living beings is atmosphere.

Green plants receive carbon dioxide from the atmosphere which is used for making food with the help of the sun light.

This is called photosynthesis.

By this process the plants create ‘carbohydrates’ in the form of food.

Carbohydrates thus, produced by plants are used as a food by all living beings.

Carbon dioxide gets dissolved in the water bodies and gets collected in the form of lime on the earth.

After dissolution of lime stone, carbon dioxide again reaches in the atmosphere.

This process is called carbonization.

In this way carbon dioxide goes on moving between the atmosphere and water bodies of the earth.

Carbon dioxide produced by breathing of plants and animals, disintegration of plants and animals and by burning fossil fuels like coal, petroleum and natural gas again returns back to the atmosphere.

In this way, the process of receiving of carbon-dioxide from the atmosphere and going back to it from the surface of the earth keeps on going continuously.

It keeps the balance between the carbon and biosphere.

 

[2] Oxygen Cycle

The amount of oxygen in the atmosphere is about 21% and all living beings use oxygen present in the atmosphere for breathing.

For the burning of fuels like wood, coal, gas etc. oxygen is essential and carbon dioxide gas is produced by their burning.

The main sources of oxygen in the atmosphere are plants and trees.

Higher the number of trees and plants, the availability of oxygen will be more.

Oxygen produced through photosynthesis by the green plants goes back to the atmosphere.

In this way the process of oxygen cycle goes on continuously.

 

[3] Nitrogen Cycle

Nitrogen is an important element for life.

The amount of nitrogen gas in the atmosphere is 78%.

The main source of nitrogen is nitrates present in the soil.

From the atmosphere, nitrogen enters into bio components through the biological and industrial processes.

Nitrogen compounds from the plants are transferred to the animals through food chain.

The process of transformation of nitrogen gas of the atmosphere into nitrogen components is called nitrogen Fixation.

Bacteria decompose dried plants and dead animals.

It produces nitrogen gas which goes back into the atmosphere.

In this way the cycle of nitrogen gas is completed.