Question

what were the reasons to call off noncooperation movement?

Answer 1

The non-cooperation movement was withdrawn because of the Chauri Chaura incident. Although he had stopped the national revolt single-handedly, on March 10, 1922, Gandhi was arrested. On March 18, 1922, he was imprisoned for six years for publishing seditious materials.

Answer 2

The Non-Cooperation Movement was called off as it had turned violent. The protesting mob attacked the police station at Chauri Chaura in the Gorakhpur district of modern Uttar Pradesh. They set fire to the police station  and 22 policemen were burned alive. As Gandhi was against the Violence, he immediately called off the Movement.