Effect of phosphorus fertilization on Zn and Cd contents in soil and corn plants

The main purpose of the trial established in 1965/66 has been to monitor the effect the use of NPK fertilizers has on yields of cultivated plants and the maintenance of soil fertility. The trial which included 20 fertilization treatments, covers a total of 8 ha and is divided into four fields (2 ha each), where four crop species (wheat, corn, sugar beet, and sunflower) are grown in rotation. The effect of a continuous use of increasing P fertilizer rates on Zn and Cd contents in the soil and corn plants were monitored in 5 different fertilization treatments from the above trial on a chernozem soil. The application of increasing P rates did not decrease the content of available Zn in the soil. However, the uptake of Zn by corn plants (stalk and leaves) was significantly higher in the unfertilized check plot than plots fertilized with increasing P rates. Although P fertilizers are considered a major anthropogenic source of soil pollution with Cd, we found that during the 30-year trial there was no significant increase in the plots treated with 50, 100 and 150 kg P2O5 ha-1 in comparation to the unfertilized check plot.