Soybean Update – Foliar Fertilizer Use in Soybean

August 6, 2021

Overall, our soybean crop in South Carolina is off to a decent start. Rains in early June delayed some small grain harvest thus delaying planting of our double crop soybean acres. The August 2nd crop progress report for South Carolina has SC at 60% bloom and 15% setting pods. At these growth stages, (R1-R3) soybean is at its most critical time for water. If you have the ability to irrigate your soybeans, make sure they are not stressing and appropriate water is being applied at this time.

With this being said, the current price of soybean is at a 5 year high, the tendency to want to apply additional inputs to increase or enhance yield potential is often on many of our minds. With additional inputs, foliar applied fertilizers are often a hot topic. A group of soybean specialists from around the country have just concluded a multi-year and multi-site (46 sites including SC) study across several yield environments where 8 different foliar fertilizers were evaluated. At the conclusion of this research, there was no yield/profit benefit from applying foliar fertilizers at the R3 growth stage to soybean that were not showing visual nutrient deficient symptoms. I anticipate a full report to be published on this research by the end of the year.

As we begin into pod set and pod fill reproductive growth stages, I would encourage you to pull soil and tissue samples and send them to the soil testing/plant analysis lab at Clemson University or a private company, if you believe that you are having any type of nutrient deficiency. Depending on the deficiency and growth stage, recommendations on corrective applications could be made.

The link for the Soil Testing Clemson Lab is here.

The link for the Plant Tissue Testing Clemson Lab is here.

If you have any questions or need more information on foliar fertilizers OR pulling/submitting a soil or tissue test, please contact your local Extension agent.