Question

why are Pea plants sown after a crop of wheat is harvested

Answer 1

Because peas are leguminous plant they are they plants which fix nitrogen of atmosphere into nitrates which have been used by wheat they are also down with wheat.

Answer 2

Pea plants are sown after a crop of wheat is harvested because the pea plants restore the soil's nitrogenous contents which are depleted during the wheat harvesting.

Nitrogen is one of the most important components of the harvesting soil which is important for the growth of the crops.

And during a major harvesting season the soil's nitrogenous contents are depleted which can be only restored by the plants like pea which fix atmospheric nitrogen in the soil with the help of the rhizobium bacterias.