Question

how can nitrogen be replenished naturally

Answer 1

Roots of leguminous plants like pea, bean and gram have nodules and a type of bacteria, called the Rhizobia Bacteria, is present in the nodules. The rhizobium bacteria helps to fix the atmospheric Nitrogen in soluble nitrogen compounds which can be used by the plants.
This process is called nitrogen fixation.
Hence, nitrogen gets naturally replenished.

Answer 2

Answer:This may help you

Explanation:

Rain storms contribute atmospheric nitrogen through rain drops that reach the soil. Legumes, such as soybeans, alfalfa and clovers, are plants that can convert atmospheric nitrogen into plant-usable nitrogen.