Objective

  • Compare soybean yield performance using a system of aggressive soil fertility and pest management practices with a more conventional, low-input system.

Study Description

Planting Date: May 22, 2014 
Location: Johnston, Iowa
Plot Layout: (4) 10 x 17.4 ft plots per entry
Factors:  
Pioneer® brand products:  
     Variety/Brand¹:      92Y75R, P28T33R
     Seeding Rate: 120,000 and 170,000 seeds/acre
     Management System:
          Intensive Management System
  • Nitrogen: 100 lb/acre side-dress N applied at R2 stage
  • Foliar Fungicide/Insecticide Application: Aproach® (9.0 oz/acre) + Asana® XL (9 oz/acre)
Conventional Management System
  • No fungicide, insecticide, or nitrogen application

Results

Soybeans - conventional management system (left) with noticeably greater symptoms of anthracnose compared to the intensive management system (right).

The conventional management system (left) had noticeably greater symptoms of anthracnose compared to the intensive management system (right.) (Johnston, Iowa; Oct 17, 2014.)

  • The Johnston farm experienced generally favorable growing season in 2014, with mild temperatures and adequate moisture.
  • Insect pressure was minimal; however, disease pressure (especially SDS and anthracnose) was prevalent.
  • Anthracnose symptoms were less severe in the intensive management system, and were likely suppressed by the foliar fungicide application.
  • The higher seeding rate had a substantial yield advantage in the intensive management system (10 bu/acre) but no advantage in the conventional system (Figure 1).
  • The yield increase in the intensive management system in 2014 was most likely primarily attributable to the foliar fungicide treatment. Nitrogen applied at R2 may also have provided some yield benefit.

Management system effect on soybean yield at seeding rates of 120

Figure 1. Management system effect on soybean yield at seeding rates of 120,000 and 170,000 seeds/acre.

Anthracnose-infected soybean stems in the conventional system prior to harvest.

A close-up view of anthracnose-infected soybean stems in the conventional system prior to harvest. (Johnston, Iowa; Oct 17, 2014)

Results (2012-2014)

Growing Conditions; Johnston, Iowa

  • 2012 – High Stress: Extreme heat/drought stress, partially mitigated by limited irrigation during July. Midseason wind caused some soybean plants to lodge.
  • 2013 – Moderate Stress: Wet spring with flooding, delayed planting till early June, and dryer later in the season.
  • 2014 – Minimal Stress: Adequate moisture/mild temperatures. SDS and anthracnose both prevalent.

3-Year Results

  • Intensive management practices provided a yield benefit over conventional practices all 3 years (Figure 3).
  • In all 3 years of the study, intensive management practices provided a greater yield advantage at the higher seeding rate (Table 1, Figure 5).
  • Seeding rate effect on yield varied among years (Figure 4). In 2012 a midseason wind event caused a high rate of lodging with 1 of the varieties at the higher seeding rate.

Table 1. Soybean yield advantage with intensive management system by seeding rate,
2012-2014.

Year Seeding Rate Difference
120,000 170,000
  -------------- bu/acre -------------
2012 7.0 16.0 + 9.0
2013 16.1 18.1 + 2.0
2014 12.4 17.1 + 4.7
Average 11.8 17.0 + 5.2

Management system effect on soybean yield, 2012-2014.

Figure 3. Management system effect on soybean yield, 2012-2014.

 

Seeding rate effect on soybean yield, 2012-2014.

Figure 4. Seeding rate effect on soybean yield, 2012-2014.

 

Management system and seeding rate effect on soybean yield, 2012-2014.

Figure 5. Management system and seeding rate effect on soybean yield, 2012-2014.


¹All Pioneer products are varieties unless designated with LL, in which case some are brands.

2012-2014 data are based on average of all comparisons made in one location through October 20, 2014. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.

Glyphosate Tolerant

Always follow grain marketing, stewardship practices and pesticide label directions. Varieties with the Glyphosate Tolerant trait (including those designated by the letter “R” in the product number) contain genes that confer tolerance to glyphosate herbicides. Glyphosate herbicides will kill crops that are not tolerant to glyphosate.