Characterization of steel slag and its effect on rice production in Latosol and acid sulfate soil

Most soils in Indonesia need soil ameliorant material. There are various ameliorant materials that can improve soil properties. The researchers propose steel slag as an alternative ameliorant material. Steel slag is a waste from steel manufacturing, and the amount is very abundant. Unfortunately, steel slag falls into the category of hazardous and toxic waste (by regulation). It is still questionable and needs verification that this material is potential for agriculture. In this study, an analysis of the characteristics (total chemical and micronutrient content) of steel slag was carried out. Besides, the steel slag was applied to Latosol and Acid Sulfate Soil (ASS) planted with rice plant to see its effects on it. The results show that steel slag is rich in Ca, Mg, P, Si, micronutrients, and low in heavy metals. The steel slag application for rice plants on Latosol and ASS show a positive effect. Rice production on soil with steel slag addition is higher than control. The optimum doses of steel slag are 6 tons/ha for Latosol and 9 tons/ha for ASS. It indicates that steel slag is a potential ameliorant material and needs reconsideration to exclude it from its category as hazardous and toxic waste.