Long-time effect of hard coal ash on the content of some elements in soil

The aim of the study was to determine the long-time effect of meliorating doses of hard coal ash (0, 100, 200, 400, 600 and 800 t ha-1) on the content of some elements in soil with the application of different organic substances: manure, straw and bark. Nineteen years after the application of ash there was still an increase in the total content of all elements in soil. Its magnitude depended on soil horizon and it was highest in the humus horizon. The increase in the content of nutrients was, in general, proportional to the applied doses of ash. In the surface layer of soil, the increase was particularly high for sodium and subsequently for calcium, magnesium, sulphur, potassium and phosphorus, arranged in the order of decreasing values. The content of elements in deeper soil layers was significantly lower than in the 0–25 cm zone. A gradual reduction in the content, together with the increase in depth, was recorded only for magnesium and sulphur. The lowest concentration of phosphorus and calcium was detected in the 51–75 cm layer, while in the case of potassium it was in the 26–50 cm zone. The substances introduced into the soil in order to reduce the impact of ash generated by hard coal combustion did not exert any significant impact on the content of elements 19 years following their application.