Variable soil types, knolls, and drought have left some
growers with extreme in-field variability of soybean maturity. There are areas in fields where the soybean
seed is 13% or less moisture adjacent to areas with green seed. The prevailing question is “When should the
grower harvest?” Obviously there is no simple answer, as each field is
different. However here are a set of guidelines to consider:
1.
The easiest answer is harvest the field at two
different times. Take what is dry today and come back in two weeks and harvest
the rest. The challenge with this approach is that today’s equipment is large
and not easily moved from field to field. Furthermore many growers rent or own
land over large areas where this is impractical and the whole field must be
taken at once. So……
2. The next simple answer is wait until the whole
field is ready to go. As noted in our article Drought
Induced Shatter, we are seeing areas across the Midwest where shattering is
occurring. The general rule of thumb is 4 seeds per square foot = one bushel
yield loss. At local cash prices surpassing $13.00 per bushel this is hard to
see happen and not harvest. Furthermore, waiting will also lead to moisture
loss in the field. As we learned last year, you do not get compensated for
harvesting below 13% moisture. So…..
3.
If growers are concerned with shatter and/or
other harvest losses the next logical approach is harvest ASAP. This opens a
whole new can of worms. Harvesting ASAP will lead to a mixture of dry, wet, and
immature (green) soybean seed. Be aware that if you harvest this mixture
regardless of the ratio, your combine moisture sensor may not detect the
correct moisture, be prepared for that initial shock when the elevator tests
the grain. Next be prepared for the dockage. Most combines will leave more
beans in the pod when they are wet or immature. These beans may end up on the ground or in
the grain tank as unthreshed soybeans. Harvesting
seed with this variability will be very similar to handling frosted soybean
seed so discounts may occur due to moisture shrink, damage (green beans are
considered damage), foreign material (this is usually higher when harvesting
wet beans), test weight, and heating. If you choose on farm storage to address
some of the dockage concerns please refer to Soybean Drying and Storage for questions.
4. The last consideration I would bring forward is that the mature areas are likely going to be the low yielding pockets due to drought whereas the yet to mature areas will likely be the higher yielding areas within the field. So, in short, which yield envirnoment would you rather focus your time and efforts to protect?
4. The last consideration I would bring forward is that the mature areas are likely going to be the low yielding pockets due to drought whereas the yet to mature areas will likely be the higher yielding areas within the field. So, in short, which yield envirnoment would you rather focus your time and efforts to protect?
The question ultimately comes down to the bottom line and
where you make the most $$$. If shatter is not occurring and you have good
equipment that does not incur significant harvest loss, will harvesting grain
that is over-dry make you more money than harvesting seed that may incur
significant dockage? My guess is yes but you tell me!
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| Image 1. Variable Maturity (M. Rankin) |
