Agriculture Reference
In-Depth Information
Prior to the invention of a viable combine, harvesting (the cutting, binding, and shocking
of the wheat plant) and threshing (separating seed from chaff ) of grain were done separately,
generally with specialized crews. Farmers would use their own reapers to cut the wheat and
then another half dozen men or so would bind (tie in bundles) and shock (stack) the grain.
After the wheat had been shocked, it had to be threshed. This was often done in the field
(although the binds could also be stored in barns), often by a custom (hired) thresherman
and his crew.
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A key feature of this process was that the grain could remain in the shocked
bundles for three or four months until threshing was completed, without serious damage to
the grain. This allowed the farmer to cut his wheat over a long time period, independent of
the timing of the actual threshing.
The introduction of the “combined harvester thresher,” now known simply as the“com-
bine,” radically changed wheat harvesting. The combine simultaneously harvests and
threshes grain and eliminates the need for rakers, gleaners, shockers, and all of the sup-
port crew that go with them. The combine made an obvious and dramatic reduction in the
number of tasks
during the harvest stage, eliminating the intermediate stages between
cutting and threshing (prediction 9.2). After the introduction of tractors with power takeoff,
one farmer could complete an entire harvest.
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The combine took one stage of production
that had potentially as many as ten tasks, and reduced them to one. It seems that no other
agricultural invention has had as great an impact on a single stage of production. Today
approximately 75 percent of all wheat farmers harvest and separate their own grain with
combines.
Perhaps even more important than reducing the number of tasks, the combine reduced the
length of the harvest stage
(T)
by compressing two long stages (binding and threshing) into a
single short stage (prediction 9.3). In the process, the combine created substantial timeliness
costs (
(L)
(d
∗
)
δ
) (predictions 9.7 and 9.8). With combines the cutting and threshing of grain
is done simultaneously, and the grain left standing in the field is exposed to natural elements
such as hail, rain, or wind that can knock it down or dampen it. Furthermore, a combine
requires grain to be ripe before cutting so that the threshing within the machine can be done
properly. According to Isern (1990), “Harvesting with the combine began seven to ten days
later than harvesting with the binder. During this time a hailstorm might level the crop,
insect pests might attack it, lodging might occur, or the grain might bleach out. In addition,
wheat that stood until dead ripe was more likely to shatter at the cutter bar” (192). Our
model predicts that all of these changes in tasks, skills, and timing encouraged family farm
harvests.
Another test of our model arises from differences in spring and winter wheat. On the
Great Plains, winter wheat is grown in the south, roughly from Texas to South Dakota,
and harvested earlier than the spring wheat grown farther north in the Dakotas, Montana,
and Canada. Spring wheat has greater timeliness costs (larger
,var
(d
∗
)
d
and var
) than winter
