Chiang Mai Journal of Science

The fertility levels of the Old Meghna River Floodplain soils in Bangladesh were evaluated using ninety four soil samples from six major soil groups namely Barda, Barurha, Chandina, Debiddar, Fuldi and Homna in order to identify problems associated with nutrient management practices and to explore suitable remedies for maintaining soil fertility. Soil pH ranged from 5.4 to 6.2 and ranked strongly acidic to slightly acidic. Soil data under different soil groups showed 1.1 to 3.06% organic matter and 0.06 to 0.14% total N. Phosphorus, K, S, B and Zn ranged from 5.5-30.0, 19.5-120.9, 32.3-220.4, 0.19-0.57 and 0.40-1.93 µg/g soil, respectively. As per ratings organic matter contents were low to medium, while N contents were very low to low. Phosphorus content in most of the soils was low to medium, K was very low to optimum, and S was high to very high. Boron contents were very low to low, where 100% soils were below critical levels. Zinc contents were low to high, where about 50% soils were below critical levels. Nitrogen deficiency is common but K, B and Zn deficiencies revealed that conditions of soil fertility as well as soil quality are alarming. The deficiencies of nutrients in soils are the effects of improper farming practices. Balanced supply of nutrients via organic and inorganic fertilizers including micronutrients is recommended to maintain soil quality and crop productivity. Soil testing, replenishment of OM, crop rotation, maintenance of optimum soil pH, control of soil erosion, and avoidance of indiscriminate use of agro-chemicals are a set of good agricultural practices that must be promoted to the farmers as a package to attain agricultural sustainability.