Question

how do plants fulfill their nitrogen requirement

Answer 1

Plants fulfil their nitrogen requirement in different ways,this process is called nitrogen cycle.They get nitrogen from lightning,from rhizobium bacteria and dead animals .

Answer 2

$\textbf{Insectivorous plants }$ are autotrophic as well as heterotrophic.

They made their own food but still eat insects.

Thier food actually lacks nitrogenous compounds, hence, to fullfill the requirement of the nitrogen they eat insects.

Thus, we can say that they eat insects to fulfill their nitrogen requirement.