What are the three different ways of nitrogen fixation?
The three ways of nitrogen fixation are:
(i) Atmospheric nitrogen
fixation: During lightning, the high temperatures and pressures created
in the air convert nitrogen into oxides of nitrogen.
(ii) Biological
nitrogen fixation: It is done by few forms of bacteria (which may be
free living like Azotobacter or symbiotic bacteria like
Rhizobium) which can convert insert nitrogen molecule into forms
like nitrates and nitrites which can be taken up by plants and used to
make the required molecules (proteins).
(iii) Industrial fixation:
It is done in the fertilizer manufacturing industries in which nitrogen
and hydrogen from atmosphere is used to form ammonia which is further
used to manufacture fertilizers such as urea, ammonium nitrate, etc.