EVERYDAY SCIENCE

Detailed explanation-1: -In the atmosphere, nitrogen exists as a gas (N2), but in the soils it exists as nitrogen oxide, NO, and nitrogen dioxide, NO2, and when used as a fertilizer, can be found in other forms, such as ammonia, NH3, which can be processed even further into a different fertilizer, ammonium nitrate, or NH4NO3.

Detailed explanation-2: -The largest reservoir of nitrogen is found in the atmosphere, mostly as nitrogen gas (N2). Nitrogen gas makes up 78% of the air we breathe. Most nitrogen enters ecosystems via certain kinds of bacteria in soil and plant roots that convert nitrogen gas into ammonia (NH3). This process is called nitrogen fixation.

Detailed explanation-3: -Nitrate is the form of nitrogen most used by plants for growth and development. Nitrate is the form that can most easily be lost to groundwater. Ammonium taken in by plants is used directly in proteins. This form is not lost as easily from the soil.

Detailed explanation-4: -Nitrogen in its gaseous form (N2) can’t be used by most living things. (Plants for example, do not have the required enzymes to make use of atmospheric nitrogen.) It has to be converted or ‘fixed’ to a more usable form through a process called fixation.

Detailed explanation-5: -Nitrogen gas from the atmosphere is fixed into organic nitrogen by nitrogen-fixing bacteria. This organic nitrogen enters terrestrial food webs. It leaves the food webs as nitrogenous wastes in the soil.