Full Paper ACAIJ, 13(5) 2013 [191-196] An Indian Journal Volume 13 Issue 5 Analytical CHEMISTRY Analytical CHEMISTRY ISSN : 0974-7419 Primary nutrient status and some related physical properties of the soils of Karnaphuli tea estate, Chittagong Muhammad Nazrul Islam 1,4 *, Abu Rayhan Mohammad Tareq 2 , M.Shamsuddin Ahmed 3 1 Department of Chemistry, University of Information Technology and Sciences (UITS), Chittagong-4225, (BANGLADESH) 2 Bangladesh Atomic Energy Commission, Dhaka, (BANGLADESH) 3 Department of Chemistry, University of Chittagong, Chittagong -4331, (BANGLADESH) 4 Yildiz Technical University, Istanbul, (TURKEY) E-mail : nazrul_bd@yahoo.com KEYWORDS Active acidity; Reserve acidity; Buffer action capacity; Organic carbon; Organic matter; Nitrogen; Phosphorus; Potassium. ABSTRACT The soil samples were collected from six different sections and three topographic positions having different depths from Karnaphuli Tea Estate of Chittagong district, Bangladesh. Active acidity, reserve acidity, buffer capacity, cation exchange capacity (CEC), organic carbon (OC), organic matter (OM), total nitrogen (TN), available phosphorous (AP) and potassium (K) were determined. The parameters have been found to vary with sampling sites, depths and topography. Soils of this studied area were acidic (pH= 4.88) in nature and reserve acidity was 4.19. Most of the soil samples showed high buffer capacity with a few exceptions. The clay content and the cation exchange capacity (CEC) values of the studied soils were found 21.78% and 19.39 meq/100g respectively. Organic carbon and organic matter contents of the soils were found 0.59% and 0.94% respectively. Average value of TN, K and AP of the soils are 0.09%, 0.11meq/ 100g and 0.02ppm sequentially. Maximum values are quite lower than that of the critical value for tea cultivation.  2013 Trade Science Inc. - INDIA INTRODUCTION Soil is a natural body comprised of solids (miner- als and organic matter), liquid, and gases that occurs on the land surface, occupies space and is character- ized by one or both of the following: horizons, or lay- ers, that are distinguishable from the initial material as a result of additions, losses, transfers, and transfor- mations of energy and matter or the ability to support rooted plants in a natural environment [1] . The cultiva- tion of plants like tea, coffee, jute etc. mostly depends on soil management, physico-chemical properties and nutrient status of soil and its availability to plants [2-5] . Productivity as well as survival of microorganisms [6,7] depend largely on active acidity, reserve acidity, buffer capacity and cation exchange capacity (CEC) of the soil. Tea has been grown in the soils of various types (loam, sandy-loam, clay-loam, sandy clay-loam) but sandy-loam and sandy clay-loam is considered to be excellent [8] . Soil organic carbon (SOC) is a significant soil characteristic, affecting many processes such as soil degradation, surface crusting, runoff, and erosion in soil [9] . It increases the cohesion of aggregates, sta- bilizes, holds soil particles together against disruption upon rainfall, and reduces erosion hazard [9] . Accurate and detailed mapping of SOC can also be used in