SOIL PREPARATION

Plough layer formed through uncontrolled traffic, cultivation on cultivated loose soil Loose soil due to deep soil preparation

Naturally compacted subsoil

A

Re-compaction of topsoil due to uncontrolled traffic, cultivation or

rmed through affic, cultivation ose soil to deep soil

smoothing of soil surface Loose soil due to deep soil preparation

Naturally compacted subsoil

acted subsoil

B

FIGURE 5.19: Schematic illustration of how a plant hole that reaches through a re- compaction layer can allow good root penetration to the loose subsoil. Inadequate plant holes cause lateral spreading of roots on top of the plough sole (A) and a potting effect in re-compacted topsoil (B) (redrawn after Louw & Van Huyssteen, 1993).

82 | SPECIAL SOIL PREPARATION STRUCTURES