ASSESSMENT OF NUTRIENT STATUS OF THE FOREST SOILS AS COMPARED TO CULTIVATED SOILS OF THE SUNDERBANS OF BANGLADESH

Abstract

An investigation was carried out to determine the nutrient status of soils of the Sundarbans of Koyra Upazila under Khulna district. Forest soils of the Sundarbans receive seawater at a regular interval. but the cultivated land inside the embankment never receives seawater. To investigate the impact of seawater on nutrient status of the forest soils as compared to cultivated soils inside the embankment, soil samples from the above two areas were collected at two different depths, surface (0-15 ern) and sub- surface (15-30 cm). The chemical analyses included soil p+I, Ee, organic matter, N. P. S. K. Ca. Mg. Na, B. Zn, Cu. Fe and Mn content in soils. The soils of the mangrove forest of Koyra Upazila were saline. but the cultivated soils adjacent to the Sundarbans (inside the embankment) were acidic to saline. EC values were higher in mangrove forest soils than cultivated land and both the pH and EC were higher in surface soils. The organic matter. N, P and S contents were higher in surface soils than that of sub-surface soils. The status of Ca, Mg and K were higher in sub-surface soils than that of surface soils. The levels of N, Ca, Mg. Na, B, Cu and Mn were higher in forest soils than that of cultivated soils. But the concentrations of Fe, P, Sand Zn were higher in cultivated soils than that afforest soils. The level of S in cultivated land was 401.4 mg kg". The low pH (5.3 to 7.3) and higher amount of S04-S indicated that the soils of cultivated land were acid-sulphate. The concentrations of micronutrients were comparatively higher in surface soils than that of sub-surface soils.