With hundreds and often thousands of acres under their control, farmers need good management tools to know what is going on in each field, and to manage the many variables that affect crop production. For the past five years, Iowa State University agronomists have been perfecting a weekly, real-time forecast to evaluate soil dynamics across specific field-scale sites and across broader regions.

Known as the Forecast and Assessment of Cropping sysTemS, the FACTS program combines information on weather, soil and crop data to provide timely quantitative answers to common questions farmers ask, like what will the yield be, how much nitrogen is still in the soil, how much soil moisture is available, and how these factors will impact yield.

Weekly updates available

The FACTS assessment is updated with new data every Wednesday through harvest. Field-scale data is collected from Iowa State University research farms, and regional data is compiled through modeling.

“The FACTS tool gives farmers and others data they cannot measure on their own,” says Sotirios Archontoulis, an ISU agronomy professor. “We go after the dynamics of important soil and crop processes to inform producers.”

Those dynamics can result in a farmer making a growing season change, or at the end of the year, help evaluate what-if scenarios regarding yield and nutrient management. FACTS accounts for interactions among soil, crop and weather factors, and is managed by a team of specialists in ISU’s department of agronomy.

The project was started in 2015 and has grown substantially over the past few years to include regional data for Illinois and Indiana. The plan is to cover 12 states in 2020.

The FACTS project also includes a corn drydown calculator, which offers predictions of corn drydown in the field, using algorithms developed for the northern Corn Belt. By providing farmers a real-time look at their soil-crop system, farmers can make predictions for their own farm about where an adjustment may need to be made. “The model will show if you have stress and where you have stress,” Archontoulis  says.

Farmers making decisions

But the decision of what to do with the information is still up to the farmer. “We do not provide recommendations; we provide key data sets for farmers to make their own decisions,” Archontoulis says.

For example, in the April 15 release, the team shows how the 2020 soil nitrogen mineralization compares with the past 35 historical years. Areas with below- and above-normal soil supply of nitrogen are illustrated — important information for nitrogen fertilization decisions. View this at the Soil Nitrogen Mineralization Index.

Archontoulis and his team have compared their predictions against specific sites at ISU’s research farms, verifying the model’s prediction and explanatory accuracy using 96 site years of data.

“We compiled the best validation data set ever, which included time-series measurements of soil nitrogen, root depth, depth to water table, crop nitrogen uptake and crop staging, in addition to yields,” he says. “It was very good to see that the model simultaneously simulated well all of these different processes, which gives us confidence we get the right answer for the right reason, a very important aspect in modeling.”

Source: ISU, which is solely responsible for information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content in this information asset.