Shifting cultivation, soil degradation, and agricultural land-use planning in the northeastern hill region of India using geo-spatial techniques

Shifting cultivation is widely practiced in the northeastern hill (NEH) region of India. It is known that the destruction of natural forests and its conversion to cropland leads to soil resource degradation. The impacts on soil due to jhuming (jhum practice followed in shifting cultivation) have not been studied adequately. Also, study of alternatives to jhum land use is lacking. In our study, a soil resource inventory of jhum lands was generated for a part of the Purvanchal Ranges of Eastern Himalaya, India to ascertain the nature of soil resource degradation due to jhuming using geo-spatial techniques. High-resolution IRS P6 LISS-IV and stereo-pair CARTOSAT-I satellite images along with digital elevation model data were used to map soil resources of jhum lands through a detailed soil survey. Typical pedons were also studied in the native forest adjacent to the jhum lands. Further, land suitability evaluation of the identified soil series for crop growth was carried out to propose alternative land-use models for jhum lands distributed over different landforms. Results indicated that soils of jhum lands were organically degraded and followed regressive pedogenesis, whereas forest soils followed progressive pedogenesis, particularly on high (650-1250 masl) and medium hills (250-650 masl). Alternaive land-use models with the inclusion of upland rice and without the inclusion of rice have been proposed. Results of the investigation should be useful for policy makers to seeking make the best use of the land resources under jhum cultivation.

Automated summary

The study examined soil resource degradation in shifting cultivation areas in the Eastern Himalayas using geo-spatial techniques, finding that soils in jhum lands were organically degraded with regressive pedogenesis compared to nearby forest soils. Alternative land-use models suitable for crop growth were proposed based on the investigation, providing valuable insights for policymakers.