Agriculture Reference
In-Depth Information
Fig. 8.1
Conditions for seeding methods (Heege and Billot
1999
)
the seed counting (Müller et al.
1994
,
1997
). For an online and on-the-go control of
the seed-density it is necessary to supply the control computer with data about the
site-specific implement speed as well (Fig.
8.2
).
8.1.1
Site-Specific Control of Seed-Density
The seed-densities for crops as listed in Fig.
8.1
vary within a wide span. The range
indicated for
e.g.
small grains goes from 150 up to 400 seeds per m
2
. Several parame-
ters bring about this wide range, such as species, variety, sowing time, water supply
of the crop and soil texture. In rain-fed areas, it is only soil texture, which lends
itself to site-specific control within individual fields.
All other parameters mentioned above usually do vary from field to field within
a farm and therefore need attention on this basis. But they can be regarded as being
constant within individual fields with present day farming techniques. On the basis
of these parameters, therefore, site-specific control within individual fields does not
make sense
The influence of soil texture and precipitation on the seed-rate needed for a high
yield of winter wheat is shown in Fig.
8.3
via a factor, by which the respective seed-
density is multiplied. With a low annual precipitation, a smaller seed-density suffices.
Because the water supply does not support a dense and lush crop. However, the
