It is known that the urban sludge resulted from clearing of the waste waters has a complex and variouscomposition due to several factors. The utilization of sludge as fertilizer in agriculture has to prevent thepollution of environment which is primarily caused by some pathogens infestation or by the increasedcontent in chemicals beyond the maximum limits admitted by the legislation. To determine the effects ofsuch sludge on the chemical compounds in soil and plant some investigations were carried out at the RIFGPitesti in 2006. The experiment involved Idared apple grown in large pots (0.785 m3). The followingexperimental scheme was organized: A factor = depth of planting substrate for applying the organic matteron it, with two graduations: a1 = 0 - 30 cm; a2 = 0 - 60 cm; B factor = type and amount of organic matterapplied (g/l substrate), with the following graduations: b1 = 0; b2 = manure 340 g/l; b3 = sludge 170 g/l; b4 =sludge 340 g/l; b5 = sludge 510 g/l; b6 = sludge 680 g/l; C factor = soil sampling depth with two graduations:c1 = 0 -30 cm; c2 = 30 – 60 cm. The soil samples were collected from pots in about 5 months after treeplanting to determine the contents of organic matter and of major macro and microelements. The same macroand microelements as well as some heavy metals were found in the water samples drained at the pot bottom.From the leaves collected from the middle of annual shoots, the macro and microelements were alsodetermined. The chemical compounds, except the total soluble salts from the soil samples showed nosignificant differences. In the case of a2 = (0 - 60 cm - planting substrate), the total soluble salts weresignificantly higher by 126% vs. a1 = (0 - 30 cm - planting substrate. The manure application (340 g/l) did notshow a significant increase in total salts versus the unfertilized control, but the sludge rates (b4-b6) led to asignificant raise by 172-238% vs. unfertilized control (b1). In case of waters drained at the pots bottom andalso of leaves, the chemical compounds did not significantly vary. Of the total chemicals from the wastewaters (Fe, Ca, N, B, Zn, Cd, Cr) only the Zn content of 4 samples had higher values than those stipulated inNTPA 001 regulation. At the c2 = (30 – 60 cm) soil depth. the total salts content was significantly higher by132% versus c1 = (0 -30 cm)
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