Soybean Management x Planting Date (NEW!)
2022 Report .pdf
Soybean Management Yield Potential
2021 Report .pdf
2020 Report .pdf
Increasing Soybean Yields by System Management
2018 Soybean Management Report Part 1: Yield results printable .pdf of this page
2017 Soybean Management Report Part 1: Yield results .pdf
2017 Soybean Management Report Part 2: Characterizations .pdf
2016 full report .pdf
Based on the Six Secrets of Soybean Success results, we are focusing on how management procedures power yield both individually and interactively with the goal of potentially identifying ‘racehorse/offensive’ and ‘workhorse/defensive’ varieties.
In 2018, we focused on the interactions of variety, fertility (N, P, and S), and foliar protection at three locations in Illinois (Yorkville, Champaign, and Harrisburg).
Research Approach
Understanding soybean yield responses to foliar protection and increased fertility may help producers better position soybean varieties. The objective of this study is to identify ‘Offensive’ soybean varieties, or varieties with adaptability to high yield environments (i.e., responsive to crop management), and ‘Defensive’ soybean varieties, or varieties with acceptable yields in low yield environments (i.e., resilience to pests and diseases, and tolerance to nutrient deficiency). In our approach, ‘Offensive’ varieties are the genotypes that combine above-average yield increases from: (i) foliar protection [PROT, foliar protection (insecticide and fungicide) versus no-foliar protection], (ii) fertility [FERT, yield change between 0 and 187 lbs/acre of MicroEssentials S10 (N, P, & S)], and (iii) yield performance under the combination of both treatments (BOTH, yield with additional fertility and foliar protection). Conversely, varieties with high yield performance under no additional fertilizer or foliar protection (Control) and low yield response to foliar protection (low PROT) were considered ‘Defensive’ varieties.
The 2018 trial evaluated 61 soybean varieties from six different brands, and maturity groups ranging from 2.1 to 4.8 (Table 1). Thirty-six varieties were evaluated at Yorkville, Champaign, and Harrisburg. The trial was planted using a precision plot planter (SeedPro 360, ALMACO, Nevada, IA) at Harrisburg, IL (2 May 2018), Champaign, IL (16 May 2018), and Yorkville, IL (19 May 2018). Plots were 16 feet in length with 30-inch row spacing and two rows in width to achieve a final population of approximately 160,000 plants acre-1. The foliar protection treatment was applied using a tractor mounted sprayer and consisted of an insecticide (Endigo® ZC; Lambda-cyhalothrin + Thiamethoxam) and fungicide (Trivapro™; Benzovindiflupyr + Azoxystrobin + Propiconazole) application at the R3 stage at a rate of 3.8 and 13.7 oz per acre, respectively. Application dates for foliar protection were 7 July 2018 (Harrisburg), 17 July 2018 (Champaign), and 25 July 2018 (Yorkville). The fertility treatment consisted of a premium MAP-based phosphorus fertilizer that also contained S, MicroEssentials S10 (MES10, 12-40-0-10S; The Mosaic Company, Plymouth, MN), applied at 187 lbs acre-1 in a subsurface band 4 to 6 inches deep immediately prior to planting using a research-scale fertilizer toolbar to provide 22 lbs N, 75 lbs P2O5, and 18 lbs S per acre.
Plots were arranged in a split-plot RCB design with four replications. The main plot was fertility (n=2) and the split-plot was foliar protection (n= 2) and variety (n=36) randomly assigned within each treatment block. Data were analyzed using analysis of variance with the PROC MIXED procedure of SAS (Version 8, SAS Institute, Cary, NC) and means were separated using Fisher’s protected LSD test at the 0.10 level of significance. Variety, fertility, and foliar protection were considered fixed effects, while block and interactions with blocks were considered random effects. At maturity, yield (bu acre-1) was measured with a plot combine and adjusted to constant moisture (i.e., 13% grain moisture concentration).