There are numerous factors that affect soybean yields - management factors, weather, variety choice. But an estimate of your yield can be calculated by looking at the number of pods, seed size and number of seeds per pod.
Here is a calculation that will allow you to estimate your soybean yield.
Pods x Seeds per Pod / Seed Size = Estimated bushels per acre
Number of Pods
Count the number of pods in 1/10,000th of an acre. This works out to 21" and the following number of rows:
- 1 row for 30" row spacing
- 2 rows at 15" spacing
- 4 rows at 7.5" spacing
Seeds per Pod
The starting point is 2.5 seeds per pod as an average, since pods can have anywhere from 1-4 seeds in them. This is a conservative estimate.
Seed Size Factor
Here the starting point is 18, which is fairly representative of 3,000 seeds per lb. If you expect larger seeds use a smaller factor, 15, and if you expect smaller seeds, possibly due to poor seed filling from lack of rain or other stress, use a larger factor like 21.
So to use the formula above, the calculation could be:
300 x 2.5 / 18 = 41.6 bu/ac
Want to try our handy calculator to estimate your soybean yield? Click on the image below to give it a try.