Question

Why are legumes, such as beans, important to the nitrogen cycle?

Answer 1

The plants that belong to the family Leguminosae are very important for Nitrogen cycle.

Explanation:

In the root nodules of these plants, rhizobium bacteria lives and are very important for nitrogen fixation. This type of relationship is called symbiosis.
Plants cannot utilize elemental nitrogen. Hence this elemental nitrogen should be fixed in to nitrates or nitrites and only then plants can utilize this. The bacteria plays a very vital role in this conversion and fixation of nitrogen. Hence Leguminous plants are very important in regard to nitrogen fixation.