Jhum cultivation, also known as the slash and burn agriculture or shifting cultivation is the process of growing crops by first clearing vegetative/forest cover on land/slopes of hills and then burning the area to increase fertility of the soil. Later, seeds are shown in that area. Jhum cultivation is practiced in some part of Manipur and is prevalent in the whole of North east region. Once the crop are harvested, the land is left fallow to allow regeneration and the area can be use again after a cycle while the cultivation for the next year is carried out in some other area.
Previously, the jhum cycle used to be for about 10 to 15 years, but with the increase in human population and reduction in the availability of jhumming area, the jhum cycle has reduced drastically to 3-4 years thus causing many problem like large deforestation, rapid soil erosion, land degradation, depletion of the soil nutrients and overall disturbance to the ecology. The reduction in jhum cycle has also reduce the productivity of the land as the fertility of the land cannot be restored in such short period.
Jhum cultivation in Manipur is confine mainly in the hill districts (Chandel, Tamenlong, Senapati and Ukhrul). And as per the available data, the area (in hectares) under jhum cultivation in Manipur has slightly decreased in the last decade.
The concern of jhum cultivation in this present environment is not only about the loss of forest cover or soil erosion but its relation with the change in climatic conditions. And the question frequently asked is the sustainability of this system of cultivation as compares to other form of farming. The dependence of the people in the hilly regions in this form of cultivation deteriorates the environment and with the continuity of the trend, its effect on climate change need to be properly studied.
Earlier when the fallow periods were long enough, shifting cultivation is a stable system in which soil fertility is maintained but the shortening of fallow periods between two crop cycles have brought certain changes to the land use pattern. Shifting cultivation which was once believed to enhances biodiversity has now been look from a negative angle. The change in the climatic conditions due to deforestation and forest degradation can also trace its roots to shifting cultivation. But many scientists is still of the view that this indigenous practices of land use has kept the forests young and growing; and it is also considered a better resource management practice.
Presently, in many places the areas for the jhum cultivation is decided after a community meeting of all the farmers. Then they began to cut the trees in their allotted areas and left it for a month to dry. The area is allowed to burned out leaving behind the big logs which are used to demarcate boundaries or separate the area into smaller compartments. Small water channels are made at the boundary along the slope of the land. These helps to carry the water during the rainy days without causing destruction to the fields. Planting of vegetables usually began at around April and after that rice cultivation starts by June-July. Harvesting is usually done during October and once the field is clear, the logs are chopped down either to convert it to charcoals or to be use as firewood. And this bring an end to one cycle of jhum cultivation.
Jhum cultivation may have its negative effect but it is a traditional agricultural practice suited for the terrains of the hill regions and it also provides food sustenance for the people. But even with the decreased in productivity, the people still continue to practice jhum cultivation and the transition of the jhum cultivator to other occupations may not be an easy process mainly due to their location and absence of other alternatives. Keeping the tradition, the practice of jhum can be improve upon by integrating with soil and water conservation measures. And the land can also be utilize for planting horticulture crops, such that a type of agro-forestry system can be brought in to the traditional method of farming in the hilly regions.