Agriculture Reference
In-Depth Information
important. Such a property could be the site-specifi c water content of the soil instead
of the rain expected. The lower the water content of the soil, the fi ner the seedbed
should be. So if recent data about the water content were mapped, both the water
situation as well as the soil break-up data could be combined in a new control map
for subsequent cultivation- or sowing operations. Yet experience with such a con-
cept up to now is not available.
The ideal concept of site-specifi c secondary cultivation would be a system of
real-time on-the-go control for soil tilth, possibly obtained in one operation based
on a tine sensor. Up to now such a concept can only be realized with power-take-off
driven implements. These allow adjusting the soil break-up by altering the speed of
the tines as well as their cuts per unit of travel distance on-the-go. Modern drives for
the
power-take-off
and for the travel speeds of tractors provide the means for such
on-the-go adjustments.
However,
drawn tools
on secondary cultivation implements are dominating in
most parts of the world. And with solely drawn tools it hardly is possible to adjust
the soil break-up on-the-go during one pass.
In short, sensing the soil break-up during cultivation in real time is feasible, but
the possibilities of using the signals are limited. The restrictions in use on the one
hand come from present defi ciencies in the precision of the weather forecasts, and
on the other hand are caused by present limits in the adjustment of drawn secondary
cultivation implements. But these conditions can change. Hopefully, in the future
the meteorological advances will provide for more precise weather forecasts, and
more cultivation implements will be at hand, which allow for adjusting the soil
break-up while operating. So the long-term outlook for site-specifi c secondary cul-
tivation still might be good.
With primary cultivation, the situation is completely different. The main objec-
tive of the control is not precise clod break-up, but the decrease of soil bulk density
via depth of operation. The latter can rather easily be adjusted on almost all imple-
ments. And furthermore, the short-term weather in the next days hardly is important
with primary cultivation. Instead of this, the depth of the primary cultivation must
be adjusted to long-term precipitation effects and to soil inherent properties. The
knowledge about these factors is available or can rather easily be obtained.
Therefore, as compared to secondary cultivation, the control of site-specifi c primary
cultivation is a matter of present day realization.
7.3.2
Precision in the Vertical Direction Within the Seedbed
A uniform soil tilth in the vertical direction within the seedbed might be adequate
with soils that do not tend to surface crusting after heavy rain and subsequent dry
weather as well as with crops that emerge rather easily. But soils with a high silt-
and low organic matter content can get crusted under the weather conditions
described above. And the seeds of some crops -
e.g.
sugar beets, spring sown small
cereals and some oil crops - emerge better if the seedbed created by secondary
