The total soil Cu was determined by flame Atomic Absorption Spectrometry before test start. Soil samples were first digested in a heating block using 5 ml of a 70% concentrated HNO3 solution in 100 mg dry soil. Temperature was increased from 80◦ C up to 110◦C until all fluid from the samples became clear and the acid was evaporated. Before AAS analysis the samples were dissolved in 0.1 M HCl The content of organic matter (OM) and pH were measured at days 0, 28, 61 and 84. The pH was measured in water. The OM content was measured as loss of ignition after 3 h at 600 ◦C