In the years 1995-1997 in the Sewage Treatment in Hajdów, prepared were plots with a 50 cm layer of sewage sludge, on which Sida hennaphrodita R. (perennial species) was cultivated as a predecessor for cultivable plants. In the year 2000, after 5-year, 4-year, and 3-year cultivation of Sida, spring rape and white mustard were sowed in these fields. Apart from these treatments, a plot with a freshly amended sludge was also included into the study. The experiment was set up using the randomised block method, with four repetitions. Both in the fresh and in the sludge used for 3 years, rape and mustard did not sprout. The sprouting and growth of these species only occurred in plots amended with sludge after 4 and 5 years of cultivation of Sida hennaphrodita. In both plots, the growth o f mustard was much weaker than spring rape. The mustard plants took much more Fe, Zn, Mn, Pb, and Cd. from the sludge cultivated for 5 years than from the sludge cultivated for 4 years. In the case of rape, there was an opposite tendency – higher amounts o f Cu, Fe, Zn and Mn were found in the plan ts from the 4-year cultivated sludge.