Alleviating soil acidity using basalt for improvement of rice (Oryza sativa L.) yield grown in an acid sulphate soil

Rice yield on acid sulfate soils in Malaysia is low, far below the national average of 3.08 t ha-1 year-1, due to Al and/or Fe (ll) ion toxicity. Acid sulfate soil and sediments contain iron sulfides (FeS2), the most common being pyrite. When exposed to the air due to drainage or disturbance, these soil produce sulfuric acid, which this make, the pH become low (≤3.5). Acid sulfate soil pose chemical, biological and physical problem to the crop. This study was conducted to ameliorate an acid sulfate soil in the Semerak- Kemasin Integrated Agriculture Development Project (IADP) located in Kelantan, Peninsular Malaysia, for rice cultivation using ground magnesium limestone (GML), and ground basalt. An incubation study was conducted in the glasshouse to alleviate the infertility of an acid sulfate using basalt with or without ground magnesium limestone (GML). Fresh soils were treated with the amendments and some microorganisms than subjected to two cycles of submergence (4 months) and drying (2 months). After every 4 months of submergence the soil and solution were taken for the analysis. The untreated soil pH was 3.44 (