Effects of selected treatments on the production of rice [Oryza sativa] in acid sulfate soils in a simulation study

Effects of the application rate of basic slag (BS10 and BS20: basic slag 10 and 20 t ha(-1), aggregate size (A20 and A30: aggregate sizes of soils, less than 20 and 20-30 mm) and groundwater level (Gw0: no influence of groundwater and Gw50: groundwater beneath 50 cm of the soil surface) treatments on the growth and yield of rice (Oryza sativa L.; BR-3 Mukta) cultivated in two pre-leached (leached for a week through tap water to remove excessive acidity and salinity from the soils before seedling transplantation) acid sulfate soils of Badarkhali (Salidic Sulfaquept) and Cheringa (Typic Sulfic Halaquept) series were evaluated in a simulation study. Optimum growth and yield of rice were recorded by the treatment combining A30Gw50BS20 in both the Cheringa (grain: 6.70 t ha(-1) and Badarkhali (5.78 t ha(-1) soils. The application of basic slag (BS20) was found to be the most effective among the individual treatments, followed by the BS10 Gw50 A30 treatments. The application of BS20 increased the grain yield in combination with the Gw0 treatment by 100% for A20, while by 122% for A30 in the Badarkhali soil. On the other hand, in the case of Gw50, these increments were 138 and 246% for A20 and A30, respectively, in the soils. However, the application of BS at the highest rate (BS20) to the Cheringa soil was not as effective as the A20 and A30 treatments in the Badarkhali soil. On the other hand, the same rate (BS20) of basic slag in combination with the Gw50 treatment increased the grain yield by 152 to 382% in the Cheringa soil compared with 138 to 246% in the Badarkhali soil. Almost similar and significant (p-0.05) effects were observed for the other yield components of rice grown in both soil series. The effect of a larger soil aggregate size (20-30 mm) was more significant on the increase of the growth and yield of rice during the 4-month growing period of rice, regardless of treatments.