with this ppt you can learn more about nitrogen cycle

1. ROHITH
NITROGEN
CYCLE

2. WHAT IS NITROGEN??
• Nitrogen is a naturally occurring element that is essential
for growth and reproduction in both plants and animals. It
is found in amino acids that make up proteins, in nucleic
acids, that comprise the hereditary material and life’s
blueprint for all cells, and in many other organic and
inorganic compounds. In addition, nitrogen comprises
about 78% of the Earth's atmosphere.

3. NITROGEN FIXATION
• Process by which free nitrogen (N2) is extracted from the
atmosphere and converted (fixed) into nitrogen compounds
which are plant nutrients (fertilizer). In nature, this process
is carried out by certain bacteria (present in the root
nodules of legumes such as beans and peas), blue-green
algae, and the lightning flash.
• All organisms cannot use the atmospheric nitrogen directly.
• However some bacteria and blue green algae are able to do
so.

4. • They convert nitrogen molecules into simpler
forms such as nitrates and nitrites.
• Nitrogen fixing bacteria like rhizobium, are found
in the roots of some of the dicot plants such as
legumes.
• These are present in special structures called
root nodules.

5. ATMOSPHERIC NITROGEN FIXATION
• Nitrogen fixation also takes place during lightening.
• At the time of lightening high temperature and pressure
created in the air converts nitrogen into oxides of
nitrogen.
• These oxides dissolve in rain water to form nitric and
nitrous acids.
• This process is know as atmospheric nitrogen
fixation.
• These acids are then utilized by various life forms

6. Root uptake
Nitrate NO3
-
Plant
protein
Soil organic
nitrogen
NITROGEN FROM THE
ATMOSPHERE
Biological
fixation
Atmospheric
fixation
Out
gassing Atmospheric Nitrogen
4 000 000 000 Gt

7. INDUSTRIAL NITROGEN FIXATION
• Human beings also fix nitrogen for their use.
• This is done by manufacturing ammonia and
urea in the industries.
• This is called as the industrial nitrogen fixation.

8. Nitrate NO3
-
Atmospheric
fixation
Out
gassin
g
Plant
protein
Atmospheric Nitrogen
Ammonium
NH4
+
Soil organic
nitrogen
INDUSTRIAL NITROGEN
FIXATION
Biological
fixation
Industrial
fixation

9. NITROGEN CYCLE
• Plants take up nitrites and nitrates and converts them
into amino acids. Which are used to make proteins.
• These proteins are consumed by animals.
• Thus we can say that nitrogen is present in both plants
and animals.
• Nitrogen is returned back to the nature when an animal
excretes or when an animal dies.

10. • Some other bacteria present in the soil converts the
various compounds of nitrogen back into nitrates and
nitrites.
• A different type of bacteria converts the nitrates and
nitrites into elemental nitrogen. ( nitrogen in the
atmosphere ).
• The process of conversion of nitrates and nitrites into
ammonia is called ammonification.
• Conversion of ammonia into nitrites and then nitrates is
called nitrification.

11. • Thus, there is a nitrogen-cycle in nature in which
nitrogen passes from its elemental form in the
atmosphere into simple molecules in the soil and
water, which get converted to more complex
molecules in living beings and back again to the
simple nitrogen molecule in the atmosphere.

12. THANK YOU