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

• 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.

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.