What is summer ploughing?

Ploughing one month in advance i.e. in the month of May for kharif crops is known as summer ploughing. There are the three usual harvests known as the kharif or autumn (June-September), the rabi or spring (October-March) and zaid or extra harvest (March-June). Summer ploughing helps to kill weeds, hibernating insects and diseasecausing organisms by exposing them to the summer heat. Summer ploughing of groundnut is always advantageous.