Soybean harvest has already commenced in Southern Illinois in some fields with early Group 2 varieties, but most fields aren’t ready yet. Because some beans are beginning to turn, we know it’s only a couple weeks away and farmers are preparing for harvest.

Of course, the two most important things are first, having the combine ready and logistics outlined and second, harvesting soybeans to capture the most bushels. Soybeans can be 13.5% at noon, 11% at 2:30 p.m. and 9% by 5 p.m. on a hot and sunny day. Timely harvest is important to maximize profits. Every farmer who grows and delivers soybeans knows this and there seems to be little they can do about it since weather is the big deciding factor.

Selling soybeans dry means lost bushels:

Moisture Level Yield Lost
  8% 5.5%
  9% 4.4%
10% 3.3%
11% 2.25%
12% 1.14%

For a field that’s yielding 75 bushels per acre at 13% moisture, harvesting at 8% results in selling 4 fewer bushels per acre. And at $10 per bushel, that is a loss of $40. Of course, during harvest you will have daily loads that will range from 14% (where you will be docked) down to 8 to 10% moisture.

To optimize the number of bushels consider these harvest tips:

  • Begin harvesting at 14% or 15% moisture. Start to harvest when some of the leaves are dry and still attached to the plant.
  • Harvest under optimum conditions. Moisture content can increase by several points with overnight dew and can decrease 4 to 6 points with sunny, warm and windy conditions.
  • Avoid harvesting when beans are driest, such as on hot afternoons, to maintain moisture and reduce shattering losses.
  • Be careful harvesting soybeans that dried down and became rewetted by rain and cool and cloudy weather. These pods will easily split and shatter.
  • If pods are brown and stems still green, make necessary combine adjustments and operate at slower speeds.
  • Adjust harvest speed and make combine adjustments to match bean conditions several times a day, as conditions change.

Lastly, avoid shatter loss. It takes about four average-sized beans per square foot to equal one bushel loss and shatter losses can exceed several bushels an acre.

If you can store beans on farm and have aeration or the ability to dry with a little heat you can begin harvesting at 16 to 18% moisture and aerate the grain down to 13% to maximize the number of bushels.

Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at

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About the Author: Dan Davidson

Soybean agronomist Daniel Davidson, Ph.D., posts blogs on topics related to soybean agronomy. Feel free to contact him at or ring him at 402-649-5919.