What is Nitrogen Cycle?

Nitrogen is an essential element that constitutes about 78% of Earth’s atmosphere, playing a vital role in the ecosystems. However, nitrogen atmospheric form is largely inaccessible to most organisms. Through a series of interconnected processes known as the nitrogen cycle, this atmospheric nitrogen undergoes transformation into forms that can be utilized by living organisms.

Nitrogen fixation, carried out by specific bacteria, converts atmospheric nitrogen into ammonia or ammonium, providing a vital source of nitrogen for plants. Subsequently, ammonification involves the decomposition of organic matter by bacteria, releasing ammonium ions back into the soil. Nitrification follows, wherein bacteria convert ammonium into nitrite and then nitrite into nitrate, a form that plants can readily absorb. Plants incorporate these nitrogen compounds into amino acids and proteins through assimilation, passing on the essential nutrient to consumers along the food chain. Denitrification, performed by bacteria in low-oxygen environments, converts nitrates back into atmospheric nitrogen, thus completing the nitrogen cycle.

Nitrogen cycle is the natural process by which atmospheric nitrogen is converted into various usable forms, like ammonia and nitrates, by bacteria for plant and animal consumption and then returned to the atmosphere through decomposition and denitrification, maintaining the nutrient balance in ecosystems. Nitrogen is an essential element for life as it is a key component of amino acids, proteins, DNA, and other biological molecules. Human activities, like agriculture and industry, can disrupt this cycle, leading to environmental issues.