Question

explain in brief how nitrogen is fixed

Answer 1

HEY!!

Certain forms of bacteria (For example: Rhizobium) are able to convert atmospheric nitrogen into usable forms such as nitrates and nitrites. Such nitrogen fixing bacteria are commonly found in the roots of legumes (plants of pulses) inside special structures called root nodules. These usable forms of nitrogen are absorbed by the plants to produce many compounds such as amino acids, which in turn form proteins.

Answer 2

They contain symbiotic bacteria called rhizobia within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. When the plant dies, the fixed nitrogen is released, making it available to other plants; this helps to fertilize the soil.