CONTENT OF COPPER, ZINC AND MANGANESE IN SOIL FERTILIZED WITH MUNICIPAL SOLID WASTE COMPOSTS

A three-year pot experiment has been conducted in order to analyze the influence of composts made from unsorted municipal solid waste and urban green waste on the total content of copper, zinc and manganese and their soluble forms in soil. The applied composts differed in maturity and the chemical composition of the matter from which they originated. It has been found that the total content of copper, zinc and manganese in soil increased as the rates of municipal solid waste composts rose, an effect which has been observed both as a direct influence and aftereffect of fertilization. The highest increase in the total content of copper was determined in soil fertilized with six-month compost from municipal solid waste. By increasing doses of the compost, the share of the soluble form of this element was reduced versus its total content. The highest increase in total zinc appeared after soil amendment with compost which matured in a heap for three months. In respect of direct effect, the share of soluble to total zinc was the highest in the treatments fertilized with one-month compost, but as an aftereffect, six-month compost resulted in the highest percentage of soluble zinc in its total amount. As for manganese, evidently higher its total concentrations were determined in soil fertilized with three-month compost compared with one- and six-month ones. The share of the soluble form of manganese to its total content decreased when older municipal waste composts or their higher doses were applied. In soil enriched with urban green waste, lower contents of heavy metals occurred than in soil fertilized with six-month compost. In the former soil, however, there was an increase in the share of soluble forms of the analyzed metals relative their total content.