Changes in the copper concentration and the content of organic complexing agents in soil solutions were followed in a pot experiment with increasing copper addition to a calcareous peat soil with and without barley plants. Samples of soil solution were collected from the soil in situ at various times during the period of plant growth. During the period 1–34 days after germination copper concentrations decreased in the solution from soils treated with copper. During the latter part of the growth period (34–100 days), copper concentration in soil solution from soil without plant-cover remained almost constant, whereas in soil solution from soils with plants the copper concentration increased to maximum values due to simultaneous increases in the content of organic complexing agents. The correlation coefficient between the content of organic complexing agents and copper concentration was 0.96 during this period.
These variations in the concentration of copper and in content of complexing agents may considerably alter the copper flux by mass-flow and diffusion to roots. re]19751028