Database Research Summaries
Identifying Best Management Practice for "Offensive/Racehorse" and "Defensive/Workhorse" Varieties

calendar_today Year of Research: 2018
update Posted On: 12/04/2019
group Fred Below (Principal Investigator, University of Illinois at Urbana-Champaign)
bookmark Illinois Soybean Association

Research Focus

The focus of this project is to identify ‘offensive/ racehorse’ and ‘defensive/ workhorse’ varieties, and the corresponding environments for their best use and optimization of yield.


  • Evaluate how variety selection impacts soybean yield individually and combined with other enhanced management factors to determine how this information can be used to improve yield based on soil placement.
  • Evaluate how weather interactions with soil placement and management level.
  • Evaluate the impact of additional N, K, S fertility treatments on yield.
  • Deliver a technology transfer component by communicating the results and opportunities to increase soybean yield to soybean producers and agronomists through in-person and online presentations.


  1. Soil pH, organic matter, and fertility levels were relatively adequate, allowing for growing
    conditions generally conducive to favorable grain yields. The 2018 crop-growing season
    experienced excessive rainfall in June across the state. During the remainder of the growing
    season rainfall was similar to the 30-year average. Throughout the growing season temperatures were fairly consistent with the 30-year average, with the exception of May being relatively hot across locations and September in Champaign.
  2. Location significantly affected grain yields, with average yields of 90.6, 86.8, and 79.0
    bu acre-1 for Yorkville, Champaign, and Harrisburg, respectively. Foliar protection
    increased soybean yield at Champaign and Harrisburg, but did not increase yield at Yorkville due to dry conditions during July and August, and low disease and insect pressure. Unlike foliar protection, additional fertility increased grain yield in Yorkville.
  3. Across all three locations, varieties had significantly different grain yields. With standard
    management (no fertility additions or foliar protection) there was a yield range of 25, 28, and 20 bu acre-1 from highest to lowest yielding varieties at Yorkville, Champaign, and Harrisburg, respectively. The greatest range in yield response among from varieties was from foliar protection at Harrisburg (36 bu acre-1).
  4. Yield responses to additional fertility among individual varieties compared to the untreated control at all locations ranged from -11.8 to +11.7 bu acre-1 indicating different genetic sensitivity to soil nutrient availability. Foliar protection application yield-responses ranged from -12.5 to +19.7 bu acre-1 and when applied in combination with additional fertility the yield changes ranged from -13.9 to +14.3 bu acre-1.
  5. The differences observed in yield performance among varieties and their interaction with
    agronomic management across environments highlights the importance of soybean genetic
    characterization in response to different agronomic management factors.


Best management practices and new technologies can increase yield.

For more information about this research project, please visit the National Soybean Checkoff Research Database.

Funded in part by the soybean checkoff.