Be ready when they’re ready.
Over the last several years of working with what I consider the top soybean producers in Lebanon County, I have learned the importance of timely harvest of soybeans. It has been my experience that once 95% of the pods turn brown, it’s time to combine about a week later. Once moistures dip below 13% a grower is essentially giving the mill soybean dry matter since they will correct the moisture to 13%. I still remember John Yocum referring to the fact that after the plants first reach harvestable moisture content, dry matter losses occur simply by the alternating day night and heavy dew.
Here is a picture of our crop teams’ soybean planting date study.
Same variety, same seeding rate, same pest management program, the only variable was the date of planting in these plots from March 28th to May 28. It is important to consider the variety since some varieties will have slight differences in the pod integrity and not tend to split as the heavy dew at night can speed up this process. There are also impacts of erect varieties that might tend to dry quickly and delays in harvest may impact those versus varieties that that tend to lay over and nestle protecting large fluctuations in dry down. This picture was taken when the early planting was ready to combine the soybeans on the left (planted two weeks earlier than the beans on the right) could be harvested two weeks before later plantings. If I were to wait as little as two weeks to harvest the plots until the rest of the planting dates matured I would lose a significant amount of soybeans from shatter losses.
If you assess the discount for bringing soybeans in a little wetter than normal there will be some cost drop the beans. In the table I have in this article you will note the relative cost per bushel of soybeans to be around 30 cents.
This is a cost that is easily overcome by the reduced harvest loss in the field at current market prices. It appears that soybean dryer than 13% return about the same to management but this does not take into account the penalty of shatter loss in the field.
I found this article from the University of Missouri useful during harvest to capture the losses that may occur during harvest.
You may also call me directly (717-270-4391) for copy of the worksheet to have on hand to take to the field and enter your own information.
Finally, if you would like more reading on this I would direct you to navigate to the Agronomy Journal Publication D. B. Philbrook 1983 that addresses this issue in more detail. B.D. Philbrook and E.S. Oplinger Harvest Loss in Soybeans.
Source : psu.edu