There has been a lot, and I mean a lot, of buzz lately around lowering soybean populations. There are many studies showing soybeans planted at lower populations either meet or exceed yields of soybeans planted at higher populations. There are also growers who are achieving very high soybean yields describing how they planted at lower populations. Here are a few things to keep in mind if you are considering lowering your soybean planting population.

Current planting population. Before I can recommend you lower your planting population, your current planting population must be considered. The term “lower” is relative not absolute. The range recommended for these lower planting populations is usually between 90,000 and 110,000 plants per acre for a final stand, not planting population. If you are already in this range, lowering would definitely not be recommended.

Planting conditions. This is something we’ve focused heavily on when it comes to planting corn, but we may be a little lackadaisical when it comes to planting soybeans. In order to achieve similar yields at lower planting populations an even stand of soybeans is key. We must use the same logic we use for corn and pay close attention to planter speed, singulation and seed depth, as well as soil conditions at planting.

Seed treatments. What does your current seed treatment consist of? Do you know? Not all seed treatments are created equal. If you want to lower your planting population be sure you are planting soybean seed with adequate seed treatment. This will help ensure a more even emergence and stand. One high-yield soybean grower recommended growers spend a third of the total cost of the seed purchase on seed treatments. For a $50 soybean this would equate to $25 worth of seed treatment to protect against early season diseases, insects, nematodes and SDS, as well as a potential inoculant, micronutrient package or growth stimulant.

Soybean seed quality. This is something to pay close attention to this year. There are many reports of poor soybean seed quality for this growing season, regardless of your soybean supplier. In most years the percent germination is between 85 – 90%, as shown on the tag. You will most likely see some of your soybean seeds this season with 5 – 10% less germination than normal. This will require a higher planting population to achieve the same number of final plants. If you are hoping for a final stand of 110,000 and your soybeans have 90% germination, you would need to plant at least 122,000 to achieve your desired population. If your soybeans only have 80% germination you now need to plant at least 138,000 to achieve your desired population.

Although lowering soybean populations has been effective there are other practices that must be done to ensure success. It requires additional management, understanding and patience. The prerequisite for fewer seeds per acre is that they have even emergence and spacing. Following these simple guidelines will help achieve your desired results.

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About the Author: Tracy Heuerman

Heuerman has worked within the Growmark system for nine years, as both a crop specialist and in her current role as a Field Sales Agronomist. She enjoys helping growers achieve maximum ROI by implementing strategies to increase yields. Raised on a family farm in south central Illinois, Tracy is still involved in growing corn, soybeans and wheat with her family. She holds a bachelor’s in agriculture economics and a master’s in plant and soil science, both from Southern Illinois University - Carbondale. She can be reached at