Agronomic Potentials of Boiler Ash Derived from Oil Palm Wastes as Fertilizer, Soil Amendment, and Liming Materials.

One potential problem with recycling power plant ashes is its variability both from fuel to fuel and within a certain fuel-type. This study obtained information on the main components of ashes derived from burning oil palm mill wastes in boilers for energy generation to obtain reference data for the development of its utility possibilities with particular emphasis on use as fertilizer, soil amendment, and liming materials. The physical and chemical properties of the boiler ash (BA) were analyzed and their test values and properties were compared with those of poultry droppings. This comparison provides information necessary for judging their suitability in comparison with widely used poultry droppings. The results show that BA has predominately sand-sized particles, with small bulk density (0.32 Mg cm-3); high electrical conductivity (433.8 d/s/cm), and pH (9.2). The chemical composition of the ash was dominated by macro-elements Ca, K, Mg, P, but are also enriched with micro-elements such as Fe, B, Zn, and Mn, The BA compared favorably with poultry droppings except in nitrogen content but has higher substantial value as an agricultural lime substitute. The results suggest that the BA may be useful for fertilizing and liming, given their phytonutrient concen- trations and neutralization potentials. However, its low nitrogen content and high electrical conductivity are a concern in situations of high application rate.