Change in the content of Pb and Cd mobile compounds in sod-podzolic soil at application increasing doses of mineral fertilizers

Abstract

Results are presented of study of seasonal dynamics of lead and cadmium mobile compounds content in arable sod-podzolic soils of long stationary trial on application of increasing doses of mineral fertilizers. The studies revealed that the concentrations of mobile compounds of elements in the soil are insignificant and do not exceed MAC and background concentrations; this fact indicates the absence of anthropogenic contamination of the studied arable soils. During the growing seasons of two years of observation, the content of mobile Pb changed from 0.08 to 1.03 mg/kg in the first year and from 1.34 to 3.10 mg/kg in the second. The content of mobile Cd was from 0.04 to 0.10 mg/kg in the first and from 0.02 to 0.05 mg/kg in the second year of observation, respectively. During the growing season, the content of mobile forms of elements was very dynamic. The maximum content of mobile lead was characteristic of the initial phase of the growing season (end of May - June) at the most favorable combination of hydrothermal factors. Clear reliable patterns in changing the content of mobile forms of cadmium during the season were not revealed. The application of increasing doses of fertilizers leads to an increase in the acidity (decrease in pH) of the arable layer of soils. However, the influence of this factor on the dynamics and content of lead and cadmium was ambiguous, which indicates a complex influence of other unaccounted soil factors.