2023
Spring Frost Risk for Soybeans in Minnesota
Category:
Sustainable Production
Keywords:
DiseaseField management Pest
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Seth Naeve, University of Minnesota
Co-Principal Investigators:
Project Code:
10-15-48-23157
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
In this project, researchers will determine the soybean frost risk for different soybean planting dates for representative locations across Minnesota. To achieve this goal, they will determine the planting date for different risk levels at a county level; assess changes in frost risk–planting date relationships in recent times; initiate development of an online tool for calculating frost risk using date, specific location, and past and forecasted weather; and initiate an investigation of soil moisture or residue cover effects on days to emergence and frost risk.
Key Beneficiaries:
#agronomists, #farmers
Unique Keywords:
#agronomy, #frost, #planting, #technology, #weather
Information And Results
Project Summary

Shifting soybean planting dates earlier has been recognized as an opportunity to increase soybean yield (Mourtzinis et al., 2019; Salmeron et al., 2014). Early planting can result in more light interception and faster early-season canopy closure; this can lessen moisture stress during the reproductive periods, lower the risk of wind and water erosion, and decrease weed competition, thereby increasing yield potential while protecting the soil. The main consideration when shifting planting dates earlier is the probability of occurrence of late frosts after crop emergence. In soybean, the growing points are aboveground and exposed after the cotyledons open. It’s fatal when all growing points are frozen. To kill soybean tissue, temperatures must be at or below 28-30 oF for several hours.

Early planting date decisions should consider the probability of late frost events. The frost risk distribution for different planting dates will be dependent on the location (latitude, position in the landscape, etc.). There are tools such as the Freeze Date Tool (Midwestern Regional Climate Center-USDA ) to provide information about the last spring freeze dates across the northcentral and northeastern United States. This kind of tool can be useful, but it doesn't take into account that from planting date to emergence the warm soil protects the plant. Thus, it seems that a precise tool to assist planting management decisions, based on frost risk in early stages, should incorporate this into the model.

The time from planting to emergence cannot be defined as a fixed period. The duration of this crop developmental stage depends on the average soil temperature. Since soil temperature is driven by ambient conditions, soybean is known to require 90 °C days (over a base temperature of 10 °C) after planting before it emerges (Castell, 2010). Therefore, we propose to combine i) this developmental predictor based on daily average temperature, and ii) data on frost date to define the probability of frost occurrence for soybean at a county level.

Project Objectives

(1) Determine the soybean frost risk for different planting dates for representative locations across MN (charts).
(2) Determine the planting date for different risk levels across MN at a county level (map).
(3) Assess changes in frost risk-planting date relationships in recent times.
(4) Initiate development of an online tool (shiny app and web-based tool) for calculating frost risk using date, specific location, and past and forecasted weather (to be completed in year 2).
(5) Initiate an investigation of soil moisture or residue cover effects on days to emergence and frost risk (to be completed in year 2).

Project Deliverables

(1) Quantification of the local risk of soybean-damaging frost associated with a planting date.
(2) Local estimations of planting dates associated with a level of frost risk. Static maps for various dates will be produced from this modeling.

Progress Of Work

Update:
? We determine the soybean frost risk for different planting dates across MN.
? We have generated several charts and insights describing different frost related variables across the state.

View uploaded report PDF file

Update:
see attached

View uploaded report PDF file

Final Project Results

Updated May 29, 2024:

View uploaded report PDF file

Benefit To Soybean Farmers

This project will provide a tool for soybean-damaging frost risk estimation that will help farmers make local decisions on early planting dates across MN.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.