ROOT
ZONE
The
root zone is the depth of soil explored by the plant roots and seldom
exceeds:
- One metre for
pastures
- 1.3 metres for
a cereal crop
- 2 metres for
lucerne.
Therefore,
a soil depth greater than the root zone has no value except perhaps,
in irrigation areas where drainage is most important. The surface
soil is more important because it provides plant nutrients but is
less useful in providing water because of surface evaporation. The
"subsoil" although providing less plant nutrients is
important as a moisture reserve particularly in dry weather.
