Soybean School: Counting Pods and Plants to Make a Yield Estimate

It’ll be a few weeks before we actually know how this year’s soybeans are going to yield, but we can get a pretty good idea now, especially if we’re willing to put some time into building a good sample size for making an estimate.

Dieter Schwarz, the new market development manager for corn and soybeans with Canterra Seeds, joins us for a discussion about making yield projections in this Soybean School episode.

Unlike corn, which usually produces a consistent number of cobs per plant, the number of pods on soybean plants vary greatly.

“The more information you gather, the more accurate your estimate is going to be,” he notes. “However, with soybeans being a highly variable crop, it’s always going to be a much tougher yield estimate than with corn.”

The process of making a yield estimate starts with knowing your plant population — the number of plants per acre.

“It’s always a good idea to come out into the field, check your stand to see how you did in terms of planting, in terms of plant health, and if there was any insect or disease pressure that adversely affected your stand,” Schwarz points out.

From there, multiply the number of plants by the average number of pods on each plant and the average number of seeds in a pod. If you kept the seed tag, you can use the seeds per pound number to calculate pounds per acre — 3,000 can be used as a generic number, notes Schwarz. Divide that number by 60 pounds per bushel and you end up with bushels per acre (see below).

Pounds per acre = (# of plants per acre x # of pods per plant x # of seeds per pod)/seeds per pound

Bushels per acre = pounds per acre/60

From there, don’t forget to factor in harvest losses, which he conservatively pegs at 10 to 12 percent.

Based on the plants pulled from the soybean plot near Portage, Manitoba in the video, Schwarz comes up with a yield projection just over 50 bushels per acre.

“There’s tremendous yield potential. It’s an indication of the year we’ve had. We’ve certainly had good moisture conditions in August, and good heat.”

Find more soybean production info in the Soybean School archives

Wake up with RealAgriculture

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAgriculture