Neutralizing Capacity of Basic Slag in Acid Sulfate Soils and Its Impacts on the Solubility of Basic Cations under Various Moisture Regimes

An incubation study was conducted with the topsoils (depth: 0-20 cm) of two different series namely Cheringa (silty clay loam, pHwater 3.6, electrical conductivity = EC 18.5 dS m-1, CEC 17.2 c mol kg-1, organic matter = OM 39.1 g kg-1, and Badarkhali (silty clay loam, pHwater 3.9, EC 19.0 dS m-1, CEC 18.40 c mol kg-1, OM 30.7 g kg-1) acid sulfate soils to evaluate the effectiveness of basic slag (BS) for the neutralization of acidity and solubility of basic cations. These soils received BS at the rate of 0, 11, 22 and 33 t ha-1 under various moisture regimes (moisture at saturated condition, i.e. 100 % moisture, moisture at field condition, i.e. 50 % and wetting-drying cycles of those 50 and 100 % moisture levels). The impacts of these treatments on some selected properties and changes in water soluble bases in these soils were studied at different periods of 180 days of incubation. The application of BS was found to be increased the pH of soils from 3.6 to 5.1 for Cheringa; 3.9 to 5.2 for Badarkhali soils during the 180 days of incubation. These increments were more striking with the highest doses of BS at 33 t ha-1 under saturated moisture conditions in both the soils. The EC of the soils had not much influenced by the application of BS, regardless of time. The treatments were exerted significant (p≤0.05) effects on the solubility of basic cations in different periods of incubation. The maximum release of the bases were recorded during 180 days of incubation under saturated moisture condition and the findings will be supportive for planning of crop production on these soils.