Agriculture Reference
In-Depth Information
Table 12.4
Accuracy of
systems for yield measurement used with root crop harvesters
Relative
calibration
error
in %
(average)
Standard
deviation of
relative error
in %
Harvester
type, crop
Measurement system
Reference
Mass accumulation
system “Silsoe”
Trailer, sugar
beets, potatoes
Godwin and
Wheeler
(
1997
)
1.1
4.0
Basket weighing
system “Tifton”
Trailed two row
basket, peanuts
Durance et al.
(
1998
)
0.2
3.1
Conveyor weighing
“Harvestmaster”
Trailed two row
side loading,
potatoes
Rawlins et al.
(
1995
)
Not recorded
4.9
Conveyor weighing
“Harvestmaster”
Trailed six row
side loading,
sugar beets
Hall et al. (
1997
)
−1.0
2.2
Conveyor weighing
“Harvestmaster”
Trailed one row
bunker, potatoes
Demmel and
Auernhammer
(
1998
)
−1.3
4.1
Conveyor weighing
“Harvestmaster”
Self propelled
six row loading,
sugar beets
Demmel et al.
(
1998
)
1.0
3.7
Conveyor weighing
“Rottmeier”
Self propelled
six row tanker,
sugar beets
Demmel et al.
(
1998
)
2.1
5.6
Friction compensated,
curved plate
Self propelled
tanker loader,
sugar beets
Broos et al.
(
1998
)
0.4
1.6
Laseroptical volume
system “Bonn”
Self propelled
cleaner loader,
sugar beets
Kromer and Degen
(
1998
)
Not recorded
4.0
Although Harvestmaster has stopped production of the HM 500 yield measurement
system (conveyor weighing principle), a number of potato custom harvesters in the
USA still is using the system to control the load of the transport trucks to avoid fi nes
for overload.
In Germany, an increasing portion of self propelled sugar beet cleaning loaders
are equipped with conveyor weighing systems also in order to avoid overloading the
trucks that take the sugar beets to the factory.
So presently there are no commercially available site-specifi c yield recording
systems offered for root crops. The fact that root crops very often grow in fi elds that
are rather uniform and fl at may have contributed to this.
12.6
Yield Measurement for Other Crops
In the USA and Australia, yield measuring systems for self propelled
cotton
pickers
and cotton strippers
have been intensively developed and evaluated since
the early 1990th. Cotton fl ow is determined either by measuring the increase of
