Maximizing Soybean Yield through Maturity Group and Population Selection Based on Soybean Planting Date
Sustainable Production
Field management Nutrient managementSoil healthTillageYield trials
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Rachel Vann, North Carolina State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

A recent verbal survey of North Carolina soybean stakeholders indicated three core areas of interest for applied soybean research: using planting date to maximize soybean yield, appropriate maturity group selection based on planting date, and population adjustments across diverse planting dates. This project seeks to provide locally generated data on these priorities. Research efforts generate information on ideal planting date for soybeans and collect data to evaluate dates of insurance coverage for soybeans, identify the appropriate soybean maturity group to be used across a wide range of planting dates, determine what soybean population should be used across various planting date and soybean maturity group combinations and shares results.

Key Benefactors:
farmers, agronomists, extension agents

Information And Results
Final Project Results

Soybean growers across North Carolina plant soybeans in a very wide production window (March-August). Optimum maturity group and seeding rate use across these planting dates will help soybean growers maximize yield. Trials were established in 2019 in Currituck, Hyde, Sampson, Union, and Yadkin Counties to evaluate the impact of soybean planting date, maturity group, and seeding rate on soybean yield. Two to eight planting dates were installed at each location. MGII, MGIII, MGIV, MGV, MGVI, MGVIIE, and MGVIIL were planted at each location at each planting date. All seed was treated with a fungicide, nematicide, and insecticide. Within each maturity group and planting date combination, five seeding rates were compared: 75,000, 100,000, 125,000, 150,000 and 175,000 seeds/A.

At the earliest planting dates (mid-March), soybeans took 19-26 days to emerge, but eventually did emerge with respectable stand. Preliminary yield results indicated that in early planting situations (mid-March through mid-April), soybean yield was optimized using later maturing varieties (=MGV). In full-season planting situations (late April through late May), soybean yield was optimized using a MGIV and V variety. In double crop planting situations (June), soybean yield was optimized using a MGIV variety. In late planting situations (July), as long as the earliest maturing varieties were avoided (MGII and III) soybean yield was similar across maturity groups. A trend identified in some of the highest yielding MGscenarios for soybeans planted before June was that these soybeans were often flowering by the middle of June, when they should be able to capitalize on maximum photosynthesis. Seed quality declines (damage and purple seed stain) were observed with MGII and III soybeans planted before May. The widespread 2019 drought across NC from late August through early October had an inevitable impact on 2019 yield results; caution should be exercised making any recommendations based on this first year of data collection.

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.