Question

nitrogen is essential nutrients for plant growth by farmer who cultivate pulses crop like green gram,black gram etc do not apply nitrogenous fertilizers during cultivating why

Answer 1

Because at the root of these type of plant which is called as leguminous plants there are some special type of bacteria which brings the atmospheric nitrogen to the roots of the plant which gave the plant it's required amount of nitrogen so farmers don't have to put nitrogenous fertilizers.

Answer 2

In the roots of this plant a bacteria rhizobium can live. It convert nitrogen into usual form and soluble in soil.