Research HighlightsSoybean Growth Monitoring Model Offers Additional Farmer Support
In this article, you’ll find details on:
- A soybean growth model has been developed by Missouri researchers to predict whether soybeans will fall below, meet or surpass the normal yield for a particular region.
- The model provides another layer of support for farmers as they make management decisions during the growing season.
- The Soybean Growth Monitoring Report is released every two weeks during the growing season so farmers can make adjustments to protect yields.
By Carol Brown
A soybean growth model developed by a Missouri researcher during the 2024 crop season is proving its validity.
University of Missouri Assistant Professor and state soybean extension specialist Andre de Borja Reis led a team in development of a prediction tool to help farmers make management decisions during the growing season.
Through a research project supported with checkoff funding from the Missouri Soybean Merchandising Council, Reis developed the tool to determine whether soybean yields will likely meet, surpass, or fall below the targeted yield for a particular region.
“This tool can help farmers decide if they need to fix a potential problem to protect yield such as an extra fungicide or foliar application,” he comments. “It is an additional layer to help make these decisions.”
Reis and his team released reports every other week that contained results from the prediction model. Results were based on data from statewide soybean extension research trials. Each trial included four planting dates with three soybean maturity groups for a total of 12 scenarios. They divided the trials into five geographic areas for reporting: the northwest, northeast, central, southwest and southeast regions of Missouri.
The tool uses soil type, important events during plant development, and in-season crop data such as biometry and phenology, Reis says. It also considers past rainfall, future forecast, and temperature, as well as plant parameters including cultivar and maturity group to reach a yield prediction.
The model doesn’t report yield in bushels per acre, Reis says, but rather if yields will deviate from historical yield. To arrive at the historical yield number, or baseline, the model applied weather data from the past 35 years and the average yields for the locations by variety and planting date over that time span to arrive at an average number of bushels per acre. The model would then begin to predict yield based on these parameters.
“The model was able to reproduce what we were observing in our plant trials across the state, and we extrapolated the data for 1000 different locations and scenarios in Missouri,” he explains. “The model can predict what will be the development from the day of simulation to the end of the season.”
The team calibrated the model to adjust its performance every two weeks as the season progressed. For example, the model predicted a given field would begin pod-setting in two weeks. Two weeks later, the team scouted the field to see if the plants were indeed pod setting as predicted. If the field had not reached pod-setting at that time, they adjusted the parameters accordingly. Over time, these enhance the ability of the model to predict results for specific regions.
“Some could argue that it doesn’t matter to know the prediction after they plant or as the growing season progresses. What is the point of knowing beforehand whether yield will be lower or higher than expected?” Reis says. “Usually, farmers want to know how well their fields are growing and whether they are on track for the best yields. Knowing whether the yield will be higher or lower than expected may help them make better crop management decisions to protect the yield that’s there.”
The bi-weekly reports were well-received by farmers and crop scouts across the state, and this year Reis is adding to the number of scenarios and locations within the five geographic regions. The team will continue to release the bi-weekly monitoring reports so farmers can follow along in order to make management adjustments.
The Soybean Growth Monitoring reports can be found on the Missouri Soybean Extension website: https://extension.missouri.edu/programs/soybean/soybean-growth-monitoring. The reports are also sent to local media, through social media, and to the Missouri Soybean Merchandising Council. New reports will begin in May. The team has delayed reports as several areas of the state received high amounts of rainfall this spring and soybeans will need to be replanted.
Additional Resources
Soybean Growth Monitoring – University of Missouri Extension webpage
Meet the researcher: Andre de Borja Reis
Published: Jun 9, 2025
The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.
