| dc.description.abstract | Bauxite is an aluminium sourced mineral. Red mud is a waste product from that process. The waste was generated from two processes, that is washing process that separate the ore from its impurities and bauxite into qualified aluminium process. The research aims to improve the utility of red mud from washing process as a growing media by ameliorants. The ameliorants used are coal bottom ash and liquid humic materials. The research was purposed to identify the chemical characteristics of red mud before and after ameliorants application, and their effect on Gmelina (Gmelina arborea roxb.) growth. This research was conducted in a greenhouse and designed with two factors: coal bottom ash with levels of 0; 80; and 160g/2kg red mud and liquid humic materials with levels of 0; 0.05; and 0.1ml/2kg red mud with three times replications. The result showed that the red mud used in this study have low levels of fertility and nutrient content. The application of coal bottom ash and liquid humic materials significantly increases the pH, levels of P2O5 available, exchangeable Ca, Mg, and cation exchange capacity (CEC). Overall H0A2 treatment with level of coal bottom ash as much as 160 tons/ha without liquid humic materials is the most efficient level to improve the chemical properties of red mud. | id |
