Phosphate Sorption Characteristics in Some Soils of Ganges Tidal Floodplains

A laboratory experiment was carried out with four representative soil series named Bajoa, Dumuria, Jhalakati, and Ghior which are collected from the Ganges tidal floodplain in Bangladesh where the main cropping pattern is rice-vegetables to determine the phosphorus adsorption. The selected physical and chemical properties of the soils were estimated in triplicate using standard methods. The highest phosphate sorption was found in Jhalakati soil using the Freundlich adsorption isotherm, in Bajoa soil using the Langmuir adsorption isotherm, and in Dumuria soil using the Temkin adsorption isotherm. The experiment revealed that the Langmuir equation provided the best fit for phosphorus adsorption data across the soils compared to the Freundlich and Temkin models. The good fit of the Langmuir model suggests that the phosphorus sorption affinity of the soils remained constant as surface saturation increased.