Fate of copper in soils from different fertilizer doses in relation to environmental risk assessment

Abstract

Total copper distribution in the soil profile was determined, depending on the type of soil and Cu dose, 5 years after the application of this element. Soil samples were taken from 5 layers to 50 cm depth from microplots filled with 3 types of soil that 5 years earlier had been treated with 5 doses of Cu: 4, 8, 12, and 16 kg ha-1. There was an uneven distribution of Cu in the soil profile. In general the Cu decreased in the subsurface layers (10-30 cm) and increased in deeper layers (30-50 cm) in relation to the surface layer (0-10 cm). Using PCA analysis, both soils and doses of similar Cu distribution in the soil profile were pointed out. The distribution pattern in the sandy soil differed from the other two sandy loam soils. Additionally, for 4 and 8 kg ha-1 doses, we recorded a similar Cu distribution as for the soil with natural Cu concentration. On the other hand, in the case of the doses of 12 and 16 kg ha-1, there was a distinctly different pattern of distribution. The maximum dose of Cu, which can be applied every 5 years, is 8 kg ha-1 for the sandy soil with a low content of organic matter and 12 kg ha-1 for sandy loam.