In the Northeast Himalayas (NEH) region, four major conventional land-use types are forest, Jhum lands,fallow Jhum lands and plantations, but little is known about their sustainability and responses to changes. We collected soil samples at two uniform depths (0-15 and 15-30 cm) from the Zunheboto district of Nagaland (India). The dataset was statistically analyzed by conducting an ANOVA-one way, principal component analysis (PCA) and calculating an additive soil quality index (SQIa). Our results confirmed that sand content, bulk density (BD), porosity, soil organic carbon (SOC), cation exchange capacity (CEC), exchangeable calcium and potassium showed significant statistical differences among soil depths depending on the land use management. PCA results showed that soil texture, BD, porosity, SOC and exchangeable cations could be considered the major indicators to define soil quality. After estimating the SQIa, Jhum soils showed the highest valuesat the surface, while at 15-30 cm soil depth, fallow Jhum soils phase showed the highest ones. The conversion from natural forest to plantation does not hamper the SQ, but their conversion into Jhum may even increaseit, for a shorter duration. However, after 1-2 year of cultivation and conversion from Jhum into fallow Jhumland, soil quality could be reduced.
Gaurav Mishra [email@example.com], Rain Forest Research Institute Indian Council of Forestry Research and Education 785001 Jorhat, Assam: India
Jesús Rodrigo-Comino [firstname.lastname@example.org], Department of Physical Geography University of Trier 54296 Trier: Germany; Soil Erosion and Degradation Research Group Department of Geography, University of Valencia Blasco Ibàñez, 28, 46010 Valencia: Spain