Explanation:

Jhum (Shifting) cultivation is a primitive practice of cultivation in States of North Eastern Hill Region of India and people involved in such cultivation are called Jhum. The practice involves clearing vegetative/forest cover on land/slopes of hills, drying and burning it before onset of monsoon and cropping on it thereafter. After harvest, this land is left fallow and vegetative regeneration is allowed on it till the plot becomes reusable for same purpose in a cycle. Meanwhile, the process is repeated in a new plot designated for Jhum cultivation during next year. Initially, when Jhum cycle was long and ranged from 20 to 30 years, the process worked well. However, with increase in human population and increasing pressure on land, Jhum cycle reduced progressively (5-6 years) causing problem of land degradation and threat to ecology of the region at large.