Invloed van het bodemmilieu op ontwikkeling en activiteit van het wortelstelsel

The purpose of the study was to elucidate the function of roots under different natural conditions. A KH 232PO 4 solution was injected in the soil and the 32P-uptake was estimated periodically in leaves or stems. After necessary corrections the root activity in the different layers of a soil profile could be estimated.
In deep humous sandy soils about 30 % of the total root activity in the layer 0-80 cm occurred in the layer 40-80 cm; in shallow soils this figure was about 10 %. In all profiles the 0-20 cm layer contributed about 50 %.

The root mass accorded with root activity but its difference between the layers was much smaller. The effect on yield was clearest in dry years.

Deeper and more intensive cultivation increased root activity and mass in the subsoil but the effect on the yield was small, depending on the type of crop and environmental conditions.

In wet soils the root activity and mass decreased with increasing depth. In dry soils the root activity in the subsoil became higher than it was in the topsoil but did not prevent a reduction in yield.