Soil Fertility – A Case Study of Shifting Cultivation Sites in Tripura

Soils under shifting cultivation were studied to monitor changes in soil fertility for a shifting cycle of three years. A decline in soil pH, organic carbon, CEC, exchangeable cations, available phosphorus and potassium were noted with the increase in shifting cultivation period from one to three years. Soils also registered decrease in water holding capacity. Available nitrogen, though declined over the shifting cycle, was, however, not in the deficient range. DTPA-extractable iron and manganese were adequately present in soils. Studies on soil humic acid showed a low degree of aromatic condensation with rise in shifting cycle but with relatively more hydroxyl, carboxylic, carbonyl or quinone functional groups and total acidity.