Ask an Agronomist
Are soybean seed inoculants something I should consider?
Jan 30, 2014
Question: What’s your experience with inoculant use in soybeans? I’ve never used one and am considering it this year.
Answer: We have done a lot of work with soybean seed inoculants here in Michigan, and I’m in favor of using one. What we’re seeing with inoculant-treated beans is that we get more nodules sooner than what we have with untreated beans. Why is this important? Because nodules make nitrogen, and soybeans use a lot of nitrogen. Typically, nodules start forming right after emergence, but they don’t start working for the plant until around V3, when the first three trifoliolate leaves are fully developed. When you have an inoculant out there, we have seen those nodules start working a little bit sooner. If it’s cool and wet and we need nitrogen in that plant, we’ve seen an inoculant help in that situation quite a bit. We think the inoculants are pretty economical for the return on investment they provide. Some of the newer products stay on the seed for a long time, as much as 120 days, and maybe even longer for the newer ones. I would encourage you to do your homework on these products. While this isn’t always true, you tend to get what you pay for, and there is quite a range in these products that are available today.
Inoculants can lead to a more robust soybean root structure, better nitrogen fixation and more yield potential. About 50% of soybean seed in the U.S. is treated with a commercial inoculant, and that’s trending up.