Influence of heavy metals on bromoxynil decay in soil from Legnica-Glogów Copper District

摘要

The aim of the studies was to determine the influence of heavy metals on bromoxynil degradation in soil. The experiments were carried out under laboratory conditions (plant growth chamber). Bromoxynil was applied to two different soils, which have similar textures, pH and organic carbon content but differed in the content of copper, lead and zinc. The soil sample that originated from Copper District was contaminated with heavy metals while another sample represented soil with low heavy metals concentration. The soil samples were taken for analyses 1 hour (initial concentration) and 2, 4, 8, 16, 32 and 64 days after treatment. Bromoxynil residue was analysed using GC/ECD (gas chromatography with electron capture detector). The differences in the contentof heavy metals affected the bromoxynil decay in soil. A high concentration of heavy metals in soil slowed down of bromoxynil degradation only in the first 2 weeks after herbicide application. After this period degradation of bromoxynil in the both soils was similar and differences between values of DT50 were not significant. The values of DT50 obtained in the experiment varied from 27 to 29 days. Moreover, the application of herbicide caused short-term decrease in microbiological activity of the soils, especially in the soil contaminated with heavy metals.