Using the Soybean Planting Decision Tool to Help Make Planting Date and Maturity Selection

Determining when to plant soybeans and selecting variety maturities are two critical decisions that Iowa farmers make each year. These two decisions greatly affect yield potential and economic return. Typically, soybean variety selection occurs months before soybean planting occurs. An added complexity is current weather conditions at the time of planting.

Through project funding by the Iowa Soybean Association and in partnership with the On-Farm Network an interactive, web-based decision tool was developed to increase the understanding of the complex interactions between maturity selection, planting date and location. The Soybean Planting Decision Tool can be found at;

The Soybean Planting Decision Tool was designed to be a decision-aid for farmers and agronomists. This tool assesses crop staging and frost risks as well as soybean yield response to maturity and planting date. The current version of the Soybean Planting Decision Tool contains a database with more than 107,000 data points that includes APSIM model simulations and field measurements. The tool is designed to allow exploration of 24 planting dates and 12 maturities based on simulated soybean yields using APSIM and a 34-year historical weather record at nine locations across Iowa. The locations used for this web tool development are centrally located within each of Iowa’s nine crop reporting district.

There are a couple of dynamics to be considered with planting date and maturity selection. Generally, there is an ideal planting date window (Figure 1). Planting earlier results in slightly lower yield potential and planting later can result in slight to large decreases in yield potential. This phenomenon dictates that farmers should plant in the ideal planting window or earlier to minimize risk of yield loss due to late planting from excessive rainfall during the planting window.

The Soybean Planting Decision Tool allows farmers and agronomists to identify the interaction of maturity selection and date of planting (Figure 2). It has been long understood and recommended that full season varieties should be planted because of greater yield potential. However, full season varieties require a longer growing season for those higher yield potentials to be realized and earlier planting comes with greater risk of crop failure due to low temperatures and late spring frosts.

The Soybean Planting Decision Tool is currently in version 1.0. The tool is being continuous adjusted as new soybean planting date and maturity trials become available. Additional versions will include greater resolution of the tool to include additional locations, historic weather, and management information. This decision-aid is a unique, multidimensional approach incorporating field research, cropping systems modeling, statistical analysis, and expert knowledge to create a web-based, interactive tool.

Soybean Planting Decision Tool developed as a decision aid to help farmers and agronomists choose soybean maturity and planting dates. The tool can also be used to understand soybean growth and maturity interactions with date of planting.

Source: Mark Licht, Ranae Dietzel, and Sotirios Archontoulis, Iowa State University 

Recent News

Late-Season Waterhemp-the Goal is Stopping Seed

In our windshield scouting of soybeans this year we have seen a lot of weedfree fields.  This makes sense given the shift toward Xtend, LibertyLink, LLGT27, and Enlist soybeans over the past several years, which provides us with effective POST options for our major weed problems – common and giant ragweed, marestail, and waterhemp (now […]

Sweetclover Hay Can be Toxic

Sweetclover can provide good nutrition to cattle because it is high in protein and energy when not mature. However, sweetclover can become toxic to cattle if fed as hay, North Dakota State University Extension livestock systems specialist Karl Hoppe cautions. Sweetclover is a biennial legume that lives for two years. It is a prolific seed […]

Corn Bottoming or Taking a Breather?

The December futures price of corn settled in a range of $3.20 – $3.25 over the last few trading sessions.  Questions regarding a price bottom for corn bubbled up in market discussions.  A yield-enhancing weather outlook and flattening ethanol production offset large export sales last week.  A change in the recent corn price pattern involves […]

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now