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50
GRAANGIDS
2016
GRAIN GUIDE
fertility, texture, structure, compactability,
stoniness and tillability. During soil surveys
the relevant soil properties are identified and
recorded by a soil scientist with the aid of soil
drills at GPS points. Soil maps are then gener-
ated, indicating the soil types as soil bodies on
the farm. These soil properties are interpreted
by the soil scientist to indicate areas with dif-
ferent potentials and applications in the fields.
These maps are then processed further to user
maps that can be loaded on the tractor’s pre-
cision screen to adjust the application of seed
and plant nutrients to the capacity of the field.
This is a quite complicated facet of precision
farming that requires advanced and relatively
expensive equipment on the tractor and imple-
ment. Some producers do start their foray into
precision farming with this technology.
Precision soil cultivation
Soil compaction and water infiltration are two
major aspects of successful grain production.
Controlled track traffic and the effective man-
agement of soil cultivation systems with the aid
of GPS technology and automatic steering sys-
tems unlock possibilities for effectively manag-
ing soil compaction. The degree and depth of
soil compaction is measured with a penetrom-
eter. This data enables you to determine the
required depth of soil cultivation exactly. The
method of breaking up soil compaction must
be adjusted to the entire production system so
that the crop is always established in soil that
is sufficiently loose within the norms. The ideal
is also for the soil not to be compacted again
where you intend planting in future. Track
traffic can be successfully controlled over a
number of years with the aid of GPS technol-
ogy and automatic steering systems. In this
system the entire field is properly loosened,
but preferably not the tractor tracks. All the
implements that will be required in the course
of the season are adapted to follow these
tracks and work only as widely as the planter,
or multiples thereof.
The most important benefits of this system are
that aggressively deep tillage is eliminated or
drastically reduced, the crop always grows in
uncompacted soil, water infiltration is promot-
ed, there is a possibility of enriching the zones
regularly planted with plant nutrients, and the
costs of mechanisation can be significantly
reduced. This is also the ideal system for com-
bining with minimum tillage and no-till.
Most new tractors of more than 120 kW have
GPS technology as standard issue, which
paves the way for driving precisely, cultivat-
ing precisely and planting in the right place.
Farming systems should be adapted to utilise
this technology for optimum production and
it is a logical point of departure when a new
tractor is purchased.
Other techniques
Technology is also available to make more
accurate fertilisation possible. Advanced sen-
sors on implements using measurements of
the chlorophyll activity in the crop are used for
this purpose.
Weed sprays can also be equipped with sen-
sors to identify weed plants in order to spray
only where the weed is present. If pests occur
only in certain areas of a field, those areas
can sometimes be identified by way of remote
sensing, or by physically scouting the field and
capturing the area with the aid of a GPS.
Martiens du Plessis, soil scientist, NWK Limited
Convert from conventional farming to
PRECISION FARMING
Continued from p. 49