BACKGROUND: Cultivation area of agricultural plastic film facilities in Korea is rapidly increasing every year; however, it accelerates the salt accumulation in soils due repeated cultivation and excessive use of chemical fertilizers. Coal ash contains various trace elements and has high potential to be used in agricultural purpose. This research is aimed to improve the quality of salts-accumulated soils and crop growth grown in plastic film facilities using soil amendment derived from coal ash and zerovalent iron powder.
METHODS AND RESULTS: Soil amendment used in the study was manufactured using coal ash with iron powder and subjected to a typical upland soil for soil quality enhancement and two salts-accumulated soils for crop growth. After one month incubation of salts-accumulated soil treated with soil amendment, soil pH was significantly increased and soil EC was decreased by about 50%, compared to the control or no soil amendment. Since the soil salts’ concentration is proportional to EC, the subjected soil amendment can be proposed as an effective way to overcome soil salts accumulation in agricultural plastic film facilities. For crop growth, the length of roots and stems increased by about 10% and the dry weight also increased by a maximum of 75%, compared to the control.
CONCLUSION: Soil amendment made from waste resources such as coal ash and zerovalent iron is found to not only be effective in improving salt-accumulated soils and crop yield but also be safe against harmful heavy metals.