Changes to Forecasting and Assessment of Cropping sysTemS website (FACTS)

May 24, 2021 1:55 PM
Blog Post

The Forecast and Assessment of Cropping sysTemS (FACTS) webpage is evolving. When it was launched in 2015, FACTS provided forecasts soil moisture, nitrogen, phenology, and crop yields at two Iowa locations. In 2016, it was expanded to six Iowa locations and in 2017 it covered 10 locations and multiple management factors within each location. After the growing season, we conducted scenario assessments of crop management decisions allowing users to see how different decisions could have impacted cropping systems performance for the past year. Until 2018, both simulated and measured data were provided on the website, making FACTS the only real-time decision support tool that released both types of data. This is very important as users could independently judge model accuracy. This also enabled a smooth transition to digital agriculture.

In 2019, the focus of FACTS evolved from field to regional scale to encompass a larger geographic area and to deliver tools that can assist with other decisions such as harvest time for corn. Therefore, it evolved from a yield forecasting tool to a platform with a collection decision support tools. In 2019, we released a regional scale tool that provides soil moisture and soil nitrogen mineralization across Iowa, Illinois, and Indiana. The regional tool included weather forecast also. In the same year, we also released the corn dry-down calculator, a tool that predicts how fast corn grain loses moisture after physiological maturity. The corn drydown tool captures the entire US Corn Belt and allow users to select fields.

In 2020, we added a historical weather tool. This is the only public product that summarizes weather data at crop reporting district level and allows monthly and annual timescales. The tool is updated the first week of every month and there are options to download aggregated weather data.

In 2021, we expanded and redesigned the regional scale tool to cover 12-states and 1,000 counties in the US Corn Belt. At the same time, we retired the very first FACTS tool, the field scale forecast and merged the soybean planting decision tool into the FACTS decision support platform.

Today’s version of FACTS includes:

Here are two examples of information included on FACTS and how we interpret this information. First, the April 2021 precipitation in central Iowa was 75% (2.4 inches) below normal (Figure 1). However, the amount of rain we typically get from January to April is 1.8 inch/month while from May to August we get 4.5 inch/month, 2.5-fold higher.  In 2016 and 2020, precipitation patterns from January to April were similar to this year. We hope 2021 to turns out like 2016, a record yield year. If instead, growing season precipitation this year is similar to 2020, yields will be much lower because Iowa soils cannot buffer a second consecutive dry year during the grain filling period as the depth to water table is already below normal in central Iowa (Fig. 2). Similar analyses can be done for other crop reporting districts.

Figure 1. Monthly precipitation in central Iowa (  

Figure 2. Simulated depth to the water table across crop reporting district and years.

Second, the 2021 soil nitrogen mineralization rate (current through 10 May 2021) estimates are low. However, this is similar to 2020 and the long-term average for this time of year. It is expected as soil temperature rises and, if soil moisture is restored, that N mineralization rates will also increase. To our knowledge, this is the first time such information is released in public to aid producers’ decision making.

Figure 3. Simulated soil nitrogen mineralization rate across crop reporting districts in Iowa (  


Sotirios Archontoulis Associate Professor of Integrated Cropping Systems

Dr. Sotirios Archontoulis is an assistant professor of integrated cropping systems at the Department of Agronomy. His main research interests involve understanding complex Genotype by Management by Environment interactions and modeling various components of the soil-plant-atmosphere continuum. Dr...

Mark Licht Assistant Professor

Dr. Mark Licht is an assistant professor and extension cropping systems specialist with Iowa State University Extension and Outreach. His extension, research and teaching program is focused on how to holistically manage Iowa cropping systems to achieve productivity, profitability and en...