Use of fertilizers or Fertilizer Application has two major global effects on the environment
Pollution of Drinking Water:
The highly mobile nutrients such as nitrogen easily finds its way to underground water and streams when added in large doses and repeated
applications.
It was found that the amount absorbed by crops is about 50%, amount fixed in organic form by microbes is approximately 30%, amount lost through denitrification is 15% while the amount usually lost by leaching is 5%.
Nitrogen is lost by leaching in form of nitrate (NO – 3 ) which in sub-soil could be reduced to nitrogen dioxide, NO 2 , which in turn induces methaemoglobinemia in infants.
There is also a risk of production of carcinogenic nitrosamines from nitrates and nitrites. World Health Organization (WHO) does not allow to exceed 10ppm NO – 3 – N so as to avoid nitrate poisoning.
Read Also: Complete List and Importance of Chemical Fertilizers for Crops
Eutrophication and Fertilizers
Excess fertilizer – nutrients especially phosphates and nitrogen that find their ways to lakes and rivers promote the growth of plants, animals
and microbes in those lakes and rivers.
The result is usually oxygen deficiency, preponderance of anaerobic organisms, accumulation of methane- ethylene, hydrogen
sulphide (H 2 S) which are toxic to aerobic organisms.
