Effects of Basic Slag, Aggregate Size and Groundwater Treatments on the Production of Chilli in Acid Sulfate Soils in a Simulation Study

A simulation study was conducted to evaluate the effects of basic slag (BS10 and BS20: basic slag 10 and 20 t ha-1), aggregate size (A20 and A30: aggregate sizes of soil, less than 20 and 20-30 mm) and groundwater depth (Gw0: no influence of groundwater and Gw50: groundwater beneath 50 cm of the soil surface) as physico-chemical amendments in two pre-leached (leached for a week through tap water to remove excessive acidity and salinity from the soil before transplantation) acid sulfate soils of Badarkhali (Salidic Sulfaquept) and Cheringa (Typic Sulfic Halaquept) series in relation to the production of Chilli (Capsicum annum L.). Maximum growth and yield of chilli were recorded by the treatment combining A30Gw50BS20 in both the Cheringa (green chilli weight: 4.82 t ha-1) and Badarkhali (4.51 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 > A30 > Gw50 treatments. The application of BS20 increased the yield in combination with the Gw0 treatment by 40% for A20, while by 107% for A30 in the Badarkhali soil. On the other hand, in the case of Gw50, these increments were 49 and 141% for A20 and A30, respectively. The application of BS at the highest rate (BS20) to the Cheringa soil was more effective compared with the A20 and A30 treatments in the Badarkhali soil. The same rate of BS20 in combination with the Gw50 treatment increased the yield by 59 to 147% in the Cheringa soil compared with 49 to 141% in the Badarkhali soil. Almost similar and significant (p≤0.05) effects were observed for the other growth parameters of chilli cultivated in both soil series.