ABSTRACT
Forest farmers in India's northeastern hill region, as elsewhere in the tropics (Nye and Greenland, 1960; Ruthenberg, 1971; Spencer, 1966; UNESCO, 1983), have sustainably managed their traditional shifting agriculture over the centuries using ‘slash-and-burn agriculture’, locally known in India as jhum. This is essentially an agroforestry system organized in both space and time. In the past, the small-scale perturbations under longer jhum cycles (the length of the forest fallow phase between two successive cycles on the same site) ensured enhanced biodiversity in the forest, with human-enriched crop and associated biodiversity; long cycles also ensured a rich nutrient capital in the soil released through slash and burn. With increasing pressure on forest resources from both outside and within the region, the jhum cycle has come down to a short five years or less (except for longer cycles still found in remote areas), with consequent land degradation and decline in soil fertility. The intensification of agriculture in many situations has led to rotational-fallow systems with little or no burning of biomass, ending up in sedentary agricultural practices.
