EDTA application on agricultural soils affects microelement uptake of plants

Chelates such as ethylenediaminetetraacetic acid (EDTA) enter soils via various sources but their effect on agricultural crops is mostly unknown. Sources of EDTA include industry, households, sewage water and agricultural practices. In a field experiment EDTA was applied in its free form at different rates (0, 150, 550, 1050kgha^-1) to study its translocation in the soil profile and to evaluate its effect on yield and mineral composition of the cultivated crop, both in the year of application (oilseed rape) and in the following year (winter wheat). The results indicate that EDTA was translocated from the soil surface to deeper soil layers in the time-frame of the experiment. EDTA was still detectable in the rooting zone 19months after application, indicating its persistence in the soil. Only the highest EDTA rate (1050kgha^-1) reduced vegetative growth of oilseed rape until stem elongation, but seed yield was not affected by EDTA application. EDTA application changed the mineral composition of plants. Higher phosphorus (P), sulphur (S), iron (Fe) and manganese (Mn) and lower cadmium (Cd) concentrations were determined in the seeds of oilseed rape. No yield effects of residual EDTA were observed for the following crop, winter wheat, but the Cd content in seeds was still lower in plots where EDTA had been applied in the previous year. Data show that EDTA application affects the mineral uptake of cultivated crops under field conditions.