Response of rice to basic slag,lime, and leaching in two saline-acid sulfate soils in pot experiments

Pot experiments were conducted to evaluate the effects of basic slag (6 to 18 t/ha), lime (CaCO₃: 3 to 9 t/ha), lime (3 t/ha) plus MnO₂ (100 mg/kg), and leaching (1.8 L/kg soils) on the growth, yield, and nutrition of rice plants grown on two saline-acid sulfate soils. The Sulfic Fluvaquent (Chakaria series) and Typic Sulfaquent (Badarkhali series) respectively showed low pH (4, 4.3); high electrical conductivity (16.2, 14.2 mS/cm), sodium adsorption ratio (13.6, 12.8), and water soluble SO₄2^? (4.6, 4.9 cmol/kg). The growth and yield response of rice to the treatments were found better in Chakaria than in Badarkhali soil. The leaching treatment was found to be the best to produce the maximum straw, and grain yield (869% increase over the control) and the highest dose of basic slag (18 t/ha) was ranked second (728%) in Badarkhali soil. But in Chakaria soil, the best response (928%) was determined with the highest dose of lime (6 t/ha) followed by the leaching (900%) treatment. The additional application of Mn0₂ (100 mg/kg) with lime (3 t/ha) significantly increased the straw and grain yields of rice by 42–47% compared with the lime 3 t/ha in both the soils. Similar effects were observed for N, P, and K concentrations in plant straw at maturity. Leaching, basic slag, and lime treatments exerted significant decrease of the Fe, Mn, Zn, and S concentrations in plants, increase of soil solution pH and optimization of some element concentrations in the plants and soil solutions.