Turning a Spray Pass into Profit: What an Iowa Soybean Trial Revealed About Mid-Season Foliar Nutrition

Every season brings its challenges, like weather extremes, tight margins, and rising expectations for yield and quality. In soybeans, the reproductive window is often where yield potential is either protected… or lost.

While soil fertility lays the foundation, there are times when conditions can’t deliver nutrients fast enough to meet demand. This could be due to dry conditions, environmental stress, or genetic potential increasing nutrient demand.

Here is where mid-season foliar nutrition, especially with micronutrients, becomes a strategic tool.

On-Farm Results: Enhancing a Planned Pass on Soybeans in Iowa with Foliar Nutrition

How can we improve grower ROI without adding operational stress?

In a recent on-farm soybean trial in Iowa, we evaluated whether adding foliar nutrition and microbial food sources to a planned insecticide and fungicide pass could improve crop performance and return on investment.

Can we turn a crop management pass into a higher-value pass by adding targeted foliar nutrition and biostimulant support?

Tank Mix Additions

• BIOZ® Diamond (10-0-1 + microbial food sources)
• Nova PULSE® (0-6-4 + Co, Mo, Zn)
• Nova FLOW® (5-10-20 + Mg)

Application timing: R2-R3

Trial Objectives

By adding this foliar program, the goal was to:

✔ Enhance foliar nutrient uptake
✔ Stimulate and improve root growth
✔ Increase stress tolerance during reproductive stages
✔ Complement crop protection performance
✔ Maximize return from an already planned application

Why This Approach Makes Sense

• Timing matters: Aligning passes is important but so is increasing uptake efficiency. Nutrient availability is critical, and soybean genetics have significantly increased yield potential leading to an increase in crop nutrient demand, especially during critical reproductive phases.
• Cost Matters: Input costs are low for this program, and potential gains are high, mitigating economic risk for the grower.
• Compatibility Matters: High quality, highly soluble, highly compatible products that tank mix safely and effectively with crop protection inputs are key.

What We Saw in the Field

1. Increased Nodulation

The combination of BIOZ Diamond, Nova FLOW + Nova PULSE applied with fungicide/insecticide showed:

• Observed root and nodule formation improvement
• Enhanced nitrogen fixation potential

Left side shows ICL Foliar Program:​ Fungicide / insecticide with: BIOZ Diamond, Nova PULSE, Nova FLOW Right side shows GSP Fungicide/ insecticide only

This is critical during reproductive stages when nitrogen demand spikes.

2. More Pods Per Plant

The ICL foliar program delivered: 72–85 pods per plant compared to 40-55 pods per plant (grower standard practice)

• 4.3% increase in yield vs GSP

3. Improved Efficiency of the Pass

By integrating crop protection and crop nutrition we were able to take advantage of already scheduled management passes for an effective well-timed nutrient application:

• Layering nutrition for a “free pass”
• Increasing the value of a fungicide/insecticide
• Delivering nutrients when the plant could use them most

4. Improved ROI with ICL Foliar Program on Soybeans

*Based on Dec 2025, Cash Price at Local Elevator, Iowa

The program showed a clear increase in estimated ROI due to better timing and smarter integration.

Key Takeaways

• Mid-season is an opportunity to protect yield
• Foliar nutrition is a precision tool, not just a rescue strategy
• Planned protection passes are nutrition opportunities—turn them into profit drivers
• Combining nutrition + biostimulants + crop protection creates a stronger system

Mid-season foliar applications allow us to optimize what you’re already doing. When conditions limit uptake and yield is on the line, well-timed foliar nutrition can be the difference between maintaining or losing yield potential—and maximizing it.

Interested to See How This Fits Your Acres?

Find an expert in your area to explore mid-season foliar strategies for corn and soybeans.