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44
GRAANGIDS
2016
GRAIN GUIDE
Contour tillage along slopes and mulch
tillage render good results in these soils.
Controlling weeds and self-sowing through
shallow tining is usually very ineffective
and additional chemical herbicides are
recommended.
3. Brown and grey soils with dry
clayey subsoils
The main soils in this group are Valsrivier,
Swartland, Sterkspruit and Estcourt.
These soils are extremely vulnerable to
water erosion.
Strict control of run-off water through
contours and mulch tillage is essential to
control erosion. However, the long-term
production potential of these soils is low
and they should generally rather be used
for planted pasture or feed production.
4. Dark clayey soils
These dark soils have a well-developed
structure and very high inherent fertility.
They are characterised particularly by
a dense cover of natural grasses in the
untilled state. Soil types in this group
include Bonheim, Milkwood and Arcadia.
These soils are very suitable for no-till
practices, but the best use for this group is
probably no tillage at all.
Summer rainfall of more than 700 mm
per year
According to the aridity index classification
and international standards this climate
zone is the only one in South Africa that is
suitable for dryland crop production. However,
the biggest part of this climate zone is
mountainous and is used for forestry. Inanda,
Hutton, Magwa, Clovelly and Avalon are
examples of soils in these areas.
Where these soils are used for crop
production, mulch or no-till practices are
very successful. However, regular liming is
necessary to maintain high yield levels. The
biological quality of the soils is maintained
through crop rotation.
References
1. MVSA Bemestingshandleiding (2007),
Hoofstuk 1.10:
Grondbewerking
en
bewerkingsriglyne
.
2. Die herstel van volhoubare graanproduksie
– Volume VI: Die produksie-omgewing (GSA,
4 Junie 2001). Hoofstuk 2:
Grondbenutting
vir droëland kontantgewasproduksie.
(Compiled by Prof ATP Bennie, UV,
Bloemfontein.)
Dr Louis Ehlers, manager: Agricultural Services:
Omnia Fertiliser – a division of the Omnia Group
(Pty) Ltd
Tillage guidelines for soils in South Africa
Continued from p. 41
Swartland and Sterkspruit
Bonheim and Milkwood
Inanda and Magwa