Agriculture Reference
In-Depth Information
Sequence of decisions
Start
deep cultivation
clay content below 12 vol.%
yes
no
deep cultivation
hydromorphic properties (recent)
yes
no
deep cultivation
organic matter below 1 vol.%
yes
no
deep cultivation
vulnerable to erosion because of slope
yes
no
shallow cultivation
Fig. 7.4
Sequence of decisions for the control of the primary cultivation depth (From Sommer and
Vosshenrich
2004
, altered)
result of geological deposits or might develop from longterm plowing at the same
depth (Gorucu et al.
2006
). The density of usual hardpans differs very substantially
from that within the topsoil. Any differences within the topsoil are smaller, hence
more diffi cult to sense.
7.2.2
Site-Specifi c Control of the Primary Cultivation Depth
7.2.2.1
Algorithm for the Control
Sommer and Vosshenrich (
2004
) developed a control system for the cultivation
depth. It is based on several soil properties and a control algorithm (Fig.
7.4
).
Whenever the
clay content
is below 12 % by volume,
hydromorphic proper-
ties
exist, the
organic matter content
is below 1 % by volume or
slope induced
erosion
might occur, deep cultivation is practiced. It should be noted that with this
control system every one of the four indications alone - or in a combination - brings
about deep operation. Whenever none of these situations exists, the control system
goes to shallow cultivation. All of these indications are not short timed and therefore
lend themselves for control via maps and their overlay (Fig.
7.5
). Particularly
regarding the clay- and the organic matter content, the maps prepared for this over-
lay control system might be used for many consecutive years, since these soil prop-
erties are rather constant over a very long time.
The hydromorphic situation might change when the drainage has been improved.
And the precautions necessary to prevent erosion depend not only on the respective
