An experimental study of the influence of the microelements on the uptake of macroelements by plants

Since trace elements are generally involved in enzymic reactions taking place within the plant an imbalance in the trace nutrient supply could be expected also to affect the uptake of major elements by roots and their translocation through the plant.

Pot experiments with ascending doses of trace nutrients were carried out with oats, tomatoes and lucerne as test crops. Yields and the chemical composition of the crops were estimated. A significant effect of Zn was found on the yield of oats, while the yield of tomatoes was affected by B and Fe.

Consequently also varying amounts of major nutrients were removed by test plants from the culture medium. Uptake of N by oats and lucerne increased with B supply. But high levels of iron reduced the uptake of P in all three test crops. The total uptake of K, Mg and Na was also affected by interactions of various trace elements but no uniformity was found in reactions of the crops tested.

This absence of uniformity suggested that the observed effects were not caused by changes in the uptake mechanism but were due to differences in the general physiological condition of the plant.