Assessment of Soil Fertility of different Landform of Jiyadhol River basin in Dhemaji District, Assam

The current study was conducted to assess the soil fertility status of flood-prone soils in the Jiyadhol river basin in the Dhemaji district of Assam. Four landform units: Piedmont Plain, Upper Alluvial Plain, Lower Alluvial Plain and Flood Plain of the Jiyadhol river basin were delineated. 170 geo-tagged soil samples collected from different location of each landform and physico-chemical properties were analyzed. The results showed that the particle density, bulk density, porosity, field capacity, permanent wilting point and available water content varied from 2.17 to 2.48 g cm-3, 1.10 to 1.68 g cm-3, 33.6 to 55.2%, 2.0 to 28.6, 0.6 to 13.8, and 1.1 to 18.7 respectively, however, pH was extremely acidic to slightly acidic, electrical conductivity range from 0.01 to 0.15 dS m-1 which was almost negligible, soils were found to be moderate to high in organic carbon, cation exchange capacity of soils range from 3.2 to 13.6 cmol(p+) kg-1, base saturation range from 33.3 to 68.1 per cent, available nitrogen, phosphorus, potassium varied from low to high and exchange calcium and magnesium range from 0.90 to 4.30, 0.50 to 3.20, respectively.The soils in mountainous places have high organic carbon content due to the sluggish rate of mineralization caused by the lower temperature. The fertile soils of flood plain may be effectively utilized for crop diversification for attaining high productivity and profitability.