Effect of mineral fertilization on the content of fluorine, lead, cadmium, zinc and manganese in cocksfoot and meadow grass

Fluorine was isolated from plant material by microdiffusion and determined potentiometrically using a fluoride ion-selective electrode. The content of lead, cadminum, copper, zinc and manganese was determined by the ASA method. Samples of cocksfoot and meadow grass were collected from plots in which mineral fertilizers (O, PK, PKN100, PKN150, PKN200, PKN250) had been used for seven years. The obtained results showed a fluorine increase in the studied grasses after using phosphoric-potassium fertilizers with an addition of ammonium nitrate (PKN130, PKN200, PKN250) but their concentrations were several dozens of times lower than those admissible for plant feeds. In most samples mineral fertilization was also found to effect manganese and zinc increases, but zinc content increased after using three fertilizers (PKN). The obtained manganese concentrations exceeded the optimal values admissible for cattle feeds. The levels of lead and cadmium did not exceed the standard admissible for plant feeds.