Improving Nutrient Use Efficiency and Profitability in Corn and Soybean Systems

Margins are tightening, fertilizer markets remain volatile, and growers are being asked to produce more with fewer inputs, fewer passes, and tighter application windows. Today’s fertility decisions must balance agronomic performance, operational efficiency, economic return, and long-term soil productivity.

ICL Technical Sales Managers — and farmers — Ryan and Zach share field-based insights into sulfur and potassium fertility strategies, the role of polyhalite fertilizer, and how multi-nutrient solutions like Polysulphate® help strengthen nutrient use efficiency, reduce operational complexity, and improve profitability in corn and soybean systems.

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Key Takeaways

• Nutrient efficiency drives profitability. Modern corn and soybean production requires fertilizer programs that improve nutrient uptake, reduce losses, and maximize return on every applied nutrient.
• Operational efficiency influences fertilizer ROI. Fewer truckloads, improved blending compatibility, and reduced field passes help growers manage labor, fuel, and time constraints during critical application windows.
• Balanced multi-nutrient fertility supports synergistic nutrient uptake. Polysulphate supplies sulfur, potassium, calcium, and magnesium in one plant-available granule that supports nitrogen assimilation, phosphorus availability, and potassium efficiency.
• Gradual nutrient release improves crop synchronization. Gradual nutrient release aligns with crop uptake curves, supporting season-long nutrient availability and improved nutrient use efficiency.
• Innovation is evolving from grower demand. Fertilizer innovations like ICL PKpluS® combine phosphorus with polyhalite sulfate-based nutrients to improve efficiency, flexibility, and fertilizer program simplicity.
• Soil health supports both short- and long-term productivity. Multi-nutrient sulfate source Polysulphate, supports soil structure, microbial activity, and nutrient cycling while maintaining neutral pH balance. With a low carbon footprint and OMRI-approval for Granular Polysulphate it combines sustainablity with profitability.

Why Nutrient Programs Are Changing

Production Challenges Facing Corn and Soybean Growers

Across North America, growers are facing tightening margins, unpredictable weather patterns, and increasingly compressed application windows. Fertility programs must now deliver consistent crop nutrition while also improving operational efficiency, reducing risk, and supporting sustainability goals.

Traditional sulfur and potassium sources — including MOP (muriate of potash), AMS (ammonium sulfate), SOP (sulphate of potash), and elemental sulfur — can introduce challenges such as:

• Elevated salt and chloride loads
• Increased seed zone injury risk
• Sulfur availability that may not align with crop demand
• Additional blending, storage, and logistics requirements

These limitations can contribute to stand establishment challenges, inconsistent nutrient availability, and increased operational pressure during planting and topdress windows.

“When margins get tighter, innovation often slows. Our goal is to bring real-world experience from both the farm and retailer perspective.” — Zach

The Growing Importance of Sulfur and Balanced Nutrition

Increasing Sulfur Deficiency in Modern Cropping Systems

Sulfur deficiencies are becoming more common across North American cropping systems. Reduced atmospheric sulfur deposition, higher yield expectations, and increased nutrient removal rates have expanded the need for season-long sulfur availability.

Sulfur availability from early vegetative growth to reproductive development plays a critical role in supporting nitrogen metabolism, protein formation, and yield development. Unlike SOP, AMS, or elemental sulfur, Polysulphate provides sulfur alongside potassium, magnesium, and calcium in a single granule, delivering a more consistent, season-long nutrient release with less variability.

The Role of Polysulphate Fertilizer

Polysulphate provides a natural, low-chloride polyhalite fertilizer source delivering four essential plant nutrients in sulfate-form:

• Sulfate sulfur (S)
• Potassium (K)
• Calcium (Ca)
• Magnesium (Mg)

All nutrients are delivered in a homogeneous granule that supports consistent field distribution and blend performance.

Unlike highly soluble fertilizers like AMS or water-insoluble fertilizers like elemental S, Polysulphate releases nutrients gradually through moisture-driven dissolution. It releases S, K, Mg and Ca in balanced sulfate-form helping synchronize nutrient availability with crop demand throughout the growing season.

Polysulphate also features a low salt index and low chloride content, supporting seed safety, root development, and soil biological activity.

Additionally, Polysulphate is produced with one of the lowest carbon footprints among commercial fertilizer products, supporting sustainability initiatives and long-term environmental stewardship goals.

Agronomic and Economic Performance in the Field

Research and Field Trial Results

• Field research across multiple cropping systems demonstrates that integrating Polysulphate into fertility programs can improve agronomic performance while enhancing operational and economic efficiency.

Season-Long Sulfur Availability

• Polysulphate provides a sulfur release profile positioned between fast-release ammonium sulfate and slower-release gypsum, supporting consistent sulfur availability throughout crop development and reducing early-season deficiency risk.

Improved Nutrient Uptake and Use Efficiency

Multiple trials have demonstrated improved nutrient uptake when Polysulphate is included in fertilizer programs, including:

• Improved nitrogen assimilation and utilization
• Greater phosphorus uptake
• Enhanced early-season vigor and plant establishment

In several research trials, improved crop performance was achieved even when total nitrogen application rates were reduced, highlighting the importance of balanced nutrient availability.

Potassium Efficiency Improvements

Research conducted in Tennessee and North Carolina demonstrated increased yields when Polysulphate was blended with MOP compared to straight MOP programs, even at reduced potassium application rates. This demonstrates how balanced nutrient delivery can improve potassium utilization efficiency.

Crop-Specific Performance Benefits

Research and grower experience have demonstrated measurable performance improvements across several major crops:

• Corn: Improved early growth, test weight, and yield stability
• Soybeans and Canola: Improved stand establishment and plant uniformity
• Alfalfa and Forage Systems: Increased crude protein and forage quality
• Peanuts: Improved calcium delivery for pod development
• Cotton: Enhanced lint quality and yield performance

Beyond agronomic performance, simplified blending and reduced application passes contribute to improved operational efficiency and overall program economics.

Application Flexibility Across Production Systems

Polysulphate integrates easily into diverse fertilizer programs and application systems, including:

• Broadcast applications
• Strip-till nutrient programs
• Air seeder and seed-zone dry fertilizer programs
• Fall, winter, or spring nutrient applications
• Blending with MOP (commonly 50/50) to maintain potassium rates while adding sulfur, calcium, and magnesium

Typical application rates range from 100–200 lb/ac depending on soil test results, yield goals, and crop requirements.

Because Polysulphate contains no phosphorus, it is also suitable for phosphorus-restricted watersheds and environmentally sensitive production regions. For growers looking for a 5-in-1, ICL PKplus offers Polysulphate with the addition of phosphorus.

Continuing Fertility Innovation: ICL PKpluS®: Multi-Nutrient Efficiency in One Application

ICL PKpluS was developed in response to grower demand for improved nutrient efficiency and operational simplicity.

ICL PKpluS combines phosphorus with Polysulphate’s sulfate-based nutrient profile in a homogeneous prill, providing five essential nutrients in one fertilizer granule.

Key advantages include:

• Lower salt index compared to many MAP, DAP, and AMS programs
• Improved nutrient distribution and root interception
• Reduced storage and blending complexity
• Fewer field passes and improved application efficiency

“There is only so much bin space and so many hours to cover a field. ICL PKpluS helps bring efficiency back into production systems.” — Ryan

The ICL Advantage: Supporting Productivity Through Balanced Nutrition

Balancing agronomic performance with economic return requires fertilizer programs that improve nutrient efficiency, support soil health, and simplify operations.

Polysulphate helps support:

• Balanced multi-nutrient fertility – supplying sulfur, potassium, calcium, and magnesium in sulfate form
• Reduced chloride and salt risk supports seed safety, root development, and stand establishment
• Nutrient release aligned with crop uptake curves for season-long availability and improved nutrient use efficiency
• Improved yield and quality potential
• Operational efficiency and fertilizer program flexibility
• Soil health and sustainability goals with improved microbial diversity, soil structure, and low carbon footprint
• ICL PKplus – all the benefits of Polysulphate plus phosphorus

“In a season where every dollar and every day matters, Polysulphate provides growers with a fertility decision that improves agronomics, strengthens economics, and builds resilience into production systems.” — Ryan

Frequently Asked Questions About Polysulphate in Corn and Soybean Fertility

What is polyhalite fertilizer and how is it different from traditional fertilizers?

Polyhalite is a naturally occurring mineral that provides four plant-available nutrients — sulfur, potassium, calcium, and magnesium — in a single granule. It offers gradual nutrient release, contains no chloride or nitrogen, and supports balanced nutrient uptake.

Why is sulfur becoming more important in corn and soybean production?

Reduced atmospheric sulfur deposition and increased crop removal rates have increased sulfur deficiency risk. Sulfur plays a critical role in nitrogen metabolism, protein formation, and overall crop productivity.

How does Polysulphate improve nutrient use efficiency?

Polysulphate supplies multiple nutrients that work synergistically to support nitrogen assimilation, phosphorus availability, and potassium utilization while releasing nutrients gradually to match crop uptake patterns.

Can Polysulphate replace MOP or ammonium sulfate?

Polysulphate is commonly used to replace a portion of MOP or ammonium sulfate in fertilizer programs. Blending allows growers to maintain potassium rates while adding sulfur, calcium, and magnesium and reducing chloride load.

When should Polysulphate be applied?

Polysulphate can be applied in fall, winter, or spring and fits broadcast, strip-till, or air seeder application systems. Its gradual nutrient release supports season-long nutrient availability.

Does Polysulphate support soil health?

Yes. Polysulphate provides sulfate-based nutrients that support microbial activity, improve soil structure, and contribute to balanced nutrient cycling while maintaining a neutral pH profile.

Does Polysulphate support sustainability goals?

Polysulphate is produced with a low carbon footprint compared to many conventional fertilizers and helps improve nutrient efficiency, which can reduce overall nutrient losses and environmental impact.

*for CEUs register and watch at Crop Life