Evaluating Soil Amendments Manufactured with Coal Combustion Ash On Soil Quality and Crop Growth.

Produced amount of coal ash has been increased annually because of high demand for power generation in Korea. Consequently, limited storage space for coal ash becomes problem recently. Coal ash is mainly recycled for cement additives or construction materials. However, utilization of coal ash for agricultural purpose is minimal. Therefore, main purpose of this research was to manufacture soil amendment using coal ash and to examine its effect on soil quality and crop growth. Soil amendment with coal ash was manufactured in the order of grounding, mixing, forming, and drying. Main materials and mixing ratio for manufacturing soil amendments were coal ash: agricultural lime: bentonite = 3:6:1 or coal ash : bentonite = 9:1. Manufactured soil amendments were applied in greenhouse and upland for cultivation of tomato and pepper respectively at the rate of 200, 400 kg/10a. Result showed that soil pH and CEC were increased as 0.2 unit and 20% respectively comparing to control(conventional NPK fertilizer) as soil amendments manufactured with coal ash were applied in greenhouse. For upland soil, CEC (80%) and available phosphate (35%) in coal ash amendments were higher than control. In terms of heavy metal concentration in soil, Cd and As were measured below detection limit and lower than danger threshold limit was measured for Cu, Pb, Zn, Ni. Comparing crop growth and quantity between control and amendments treated plots, about 16% higher crop quantity was observed at the amendments treated plot than control. In conclusion, soil amendments manufactured with coal ash showed no detrimental effect on soil quality and crop growth comparing to conventional treatment. Furthermore, enhanced crop growth and quantity were observed. Based on those result, coal ash can be utilized for source of soil amendments and more research is necessary for expanding the usage of coal ash in agricultural field.