Question

why are pulses alternated with crops like wheat and paddy

Answer 1

Pulses are grown alternatively with wheats and paddy so that the land continues to regain nitrogen. Pulses are leguminous plants which have nitrogen fixing bacteria 

Answer 2

Pulses are grown alternatively with wheats and paddy so that the land continues to regain nitrogen. Pulses are leguminous plants which have nitrogen fixing bacteria in their root nodules which replenish the ibuprofen