9 Fertility Problems Polysulphate® Solves in Modern Crop Nutrition

As a ag community, we are facing increasing pressure. Input costs continue to rise, regulations are tightening, weather extremes are more frequent, and yield expectations remain high. While sulfur, potassium, calcium, and magnesium are all essential nutrients, many traditional fertilizer programs address them separately — often leading to inefficiencies, nutrient gaps, and unnecessary complexity.

Polysulphate® is a product we get excited about working with at ICL. It’s a naturally occurring, multi-nutrient fertilizer— polyhalite— that delivers potassium (K), sulfur (S), calcium (Ca), and magnesium (Mg) together in a low-salt, sulfate-based granule. It’s hard to compare it to anything on the market, because it is so unique in its properties. Its gradual nutrient release supports balanced uptake, improved nutrient use efficiency, and more consistent crop performance throughout the season.

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We’ve broken it down to explore nine common fertility problems Polysulphate® helps solve:

1) Is your sulfur source limiting yield potential?

Sulfur Deficiency Isn’t the Only Problem

• Problem: Many sulfur fertilizers are unreliable, delivering sulfur too quickly or too slowly, without supporting nutrients. This can create nutrient imbalances, timing gaps during peak demand, and added salt stress—reducing overall fertilizer efficiency and yield response.
• Solution: Polysulphate® (polyhalite) is more than just sulfur. It supplies sulfur alongside potassium, calcium, and magnesium in sulfate form. These nutrients are released gradually and together, supporting balanced uptake and consistent crop performance throughout the growing season. Polysulphate® is also OMRI approved.

2) Are fertilizer salts compromising soil health and limiting nutrient uptake?

Salt and Chloride Stress Can Compromise Soil Function

• Problem: High-salt and chloride-based fertilizers can restrict water and nutrient uptake, disrupt microbial activity, stress early root development, and reduce nutrient use efficiency—especially in tight soils or cool early-season conditions.
• Solution: Polysulphate® delivers nutrients in a low-salt, low-chloride sulfate form. It reduces sodium (Na) levels in sodic soils and increases nutrient availability in high pH soils (pH > 7.5). This helps protect roots, improve nutrient uptake, and support efficient nutrient cycling — helping crops convert nutrition into yield and profit. Early research shows Polysulphate® also supports greater microbial diversity.

3) Is your potassium source under performing?

Choosing the Right Potassium Source for Yield and Efficiency

• Problem: Some potassium fertilizers supply K rapidly but lack supporting nutrients or contain high chloride and salt levels. These factors can stress roots, limit potassium availability, and reduce nutrient efficiency in certain soils and seasons.
• Solution: Polysulphate® gradually supplies low chloride sulfate-based potassium, along with sulfur, calcium, and magnesium. This supports balanced nutrition, improves potassium efficiency, and delivers more, higher quality yields— either applied alone or as part of a blend.

4) Are you applying NPK but not seeing the expected return?

Applied NPK Isn’t Turning Into Yield

• Problem: Nitrogen and phosphorus uptake can slow when sulfur, potassium, calcium, and magnesium are deficient. This reduces nutrient use efficiency (NUE), increases losses, and limits yield response to applied fertilizer.
• Solution: Polysulphate® improves NPK efficiency by supplying season-long sulfur, calcium, magnesium, and potassium in sulfate form—supporting nitrogen assimilation and nutrient uptake so growers can capture more yield from existing fertilizer programs and, in some cases, reduce rates.

5) Is your fertility program adding cost and time without improving yield?

Precision doesn’t always mean more field passes or more money.

• Problem: Multiple products, additional blends, and extra passes can increase operational cost and complexity without guaranteeing improved nutrient efficiency or yield.
• Solution: Polysulphate® delivers four nutrients in one application reducing blending requirements, field passes, and overall program complexity. It’s available in granular, standard (fine), and Premium (spherical prill) grades for operational flexibility, blends easily with other products, and has excellent storage and application specs.

6) Does sulfur availability drop before peak crop demand?

Avoid Classic Mid-Season Sulfur Collapse

• Problem: Chasing late-season sulfur deficiency instead of preventing it. Early-season growth may look strong, but sulfur availability can decline during rapid uptake periods. Nitrogen efficiency drops, crops yellow, and yield suffers — often leading to additional nitrogen applications instead of correcting sulfur.
• Solution: Polysulphate® provides gradual, season-long sulfate release, preventing mid-season sulfur deficiency and supporting nitrogen assimilation and nutrient uptake when crop demand is highest.

7) How do you maintain yield while optimizing nitrogen inputs?

Maintain Yield With Less Nitrogen (NUE)

• Problem: Nitrogen costs and uptake are volatile, regulations are tightening, and yield expectations remain unchanged — shifting the focus from application rate to efficiency.
• Solution: Polysulphate® improves nitrogen use efficiency by supporting sulfur-driven assimilation with sulfur and sulfate-based calcium and potassium, helping growers produce more yield and protein per pound of nitrogen applied.

8) Is your fertility program resilient to weather variability?

Nutrient Performance Under Extreme Weather Stress

• Problem: Heavy rainfall increases nutrient leaching, while drought limits uptake. The same fertility program can perform very differently year to year under variable conditions.
• Solution: Polysulphate® reduces leaching risk compared to highly soluble sources, supports root health, soil structure and water uptake, improving resilience under both wet and dry conditions.

9) Is gypsum availability or cost limiting your calcium strategy?

A Smarter Alternative to Gypsum for Calcium Nutrition

• Problem: Gypsum availability and transportation costs are increasingly challenging. Gypsum also supplies calcium alone, often requiring additional products to meet potassium or magnesium needs — increasing cost and complexity.
• Solution: Polysulphate® delivers calcium in a more soluble form than gypsum, increasing availability of Ca at lower application rates. Its gradual nutrient release improves efficiency and delivers a significantly lower carbon footprint than gypsum while supporting soil structure and nutrient balance.

Providing Value for Every Acre

As fertility programs face increasing economic, regulatory, and environmental pressure, efficiency matters more than ever. Polysulphate® addresses multiple nutrient challenges at once — reducing sulfur deficiency, improving potassium, phosphorus and nitrogen use efficiency, and supporting soil health, while simplifying fertility programs.

By delivering four essential nutrients in a low-salt, sulfate-based form, Polysulphate® helps get more value from every input and more consistency from every field.

Learn where Polysulphate® fits in your nutrient program, explore trial data, or connect with an expert to find a local retailer.

◉ I’m a Grower
Connect me with a Polysulphate retailer

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I want to buy Polysulphate