EVALUATION OF IMPACT OF FERTILIZATION WITH MANURE, MUNICIPAL SEWAGE SLUDGE AND COMPOST PREPARED FROM SEWAGE SLUDGE ON CONTENT OF Mn, Zn, Cu, AND Pb, Cd IN LIGHT SOIL

The aim of the research was to estimate the impact of fertilizing with manure, sewage sludge and compost prepared from sewage sludge on the content of total and soluble forms of Mn, Zn, Cu as well as Pb and Cd in light soil. A pot experiment was set up with the split plot method in 2006. The first factor objects were types of fertilizers: manure, municipal sewage sludge, compost prepared from sewage sludge. The second factor consisted of doses of manure and organic fertilizers incorporated into the soil, expressed as amounts of nitrogen (0.26 and 0.52 g N per pot). In the second year mineral fertilizing was applied in a dose of 0.30 g N.pot(-1) and 0.72 g K.pot(-1). Soil used in the experiment was taken from Ap level and had grain size distribution of light loamy sand. The soil was acidic (pH in 1 mol KCl.dm(-3) - 5.13) and moderately abundant in available phosphorus, potassium and magnesium. The content of microelements in soil before the experiment was below the permissible concentrations given in the Ordinance of the Minister of Environment of 9.09.2002 on quality standards of soils and ground (Journal of Law, 2002, no. 165 item 1359). As regards the contamination of soil with Cu, Mn, Ni, Pb, Zn, the content of these heavy metals, according to IUNG classification, was 0, which stands for natural content, although the content of Cd was raised up to I(o). It has been found out that fertilizing with manure, sewage sludge and compost prepared from sewage sludge increased, in direct and successive effect, the content of total and soluble in 1 mol HCl.dm(-3) forms of microelements. In the case of soil fertilized with organic fertilizers, first degree contamination with cadmium and nickel occurred (exceeding natural content in soil). The application of manure and sewage sludge, in turn, raised the content of lead. On the basis of the mean share of soluble forms in the total content in soil from objects fertilized with organic fertilizers, the microelements could be ranked as follows: Cu > Pb > Ni > Cd > Mn > Zn in the first year of the research, and Cd > Ph > Cu > Mn > Zn > Ni in the second year.