Why Potatoes Need More Than NPK

Potato growers know that achieving consistent, high-quality yields isn’t just about nitrogen, phosphorus, and potassium. Behind every premium crop is a balanced nutrition program—one that includes secondary macronutrients like sulfur, magnesium, and calcium. These nutrients work in tandem with the Big Three to support critical physiological processes, mitigate deficiencies, and promote the development of high-quality potatoes with improved market appeal and culinary attributes. 

That’s where Polysulphate® stands out. 

What Is Polysulphate? Benefits of a Multi-Nutrient Fertilizer for Potatoes

Polysulphate is a naturally mined, multi-nutrient fertilizer that delivers sulfate-based sulfur (S), potassium (K), magnesium (Mg), and calcium (Ca) in a single, low-salt, low-chloride granule. Its unique composition helps optimize soil and plant health, providing steady nutrient availability that matches potato uptake throughout the season. 

A Balanced, Low-Salt Multi-Nutrient Fertilizer for Potatoes

Unlike conventional fertilizers that can cause salt stress or leaching losses, Polysulphate’s gradual nutrient release supports uniform growth from planting to harvest. For potatoes—sensitive to chloride and uneven nutrient uptake—this balanced approach means improved yield potential, better tuber uniformity, and reduced physiological disorders like hollow heart. 

The low chloride content of Polysulphate helps protect potato quality, reducing the risk of defects and processing quality issues. Its slow-release sulfur also improves nitrogen efficiency, supporting steady growth without excessive foliage production.

How Polysulphate Improves Tuber Quality and Uniformity

Proven Field Trial Results: Polysulphate Performance Across North America

Potatoes have shown some of the most consistent responses to Polysulphate across ICL’s North American field trials. Over four growing seasons in Minnesota, Michigan, North Carolina, Manitoba, and Prince Edward Island, trials showed total yield increases ranging from 4.3% in Manitoba to 77% in North Carolina compared to controls. 

Beyond yield, trends included: 

• increased nitrogen-use efficiency 

• reduced hollow heart 

• better fry quality 

Key metrics for both fresh and processing markets. Whether under rainfed or irrigated conditions, Polysulphate improved marketable yields across varied soil types and production systems. 

What stands out is its ability to supply four nutrients in one product. This helps our growers and retailers simplify fertilizer programs, potentially reducing input costs or improving ROI depending on how it’s used alone or in a blend.  

It’s not just about the rate—it’s about selecting the right source to support balanced nutrition when the crop needs it most, ultimately driving performance. 

The Role of Calcium and Magnesium in Potato Health and Yield

Why Do Calcium and Magnesium Matter for Potatoes?

Calcium is the cornerstone of tuber structure. It strengthens cell walls, reduces internal browning, and helps prevent hollow heart—all while improving fry color and texture. Magnesium, meanwhile, fuels photosynthesis and starch formation, directly influencing yield and dry matter. Together, these nutrients support healthy root systems, sustained nutrient uptake, and the consistent quality buyers look for. With Polysulphate, we get both Ca and Mg, working in tandem.  

Sustainable, Low-Chloride Fertilizer for Modern Potato Production

Polysulphate is Sustainable and Agronomically Smart

Different from other multi-nutrients, is that fact that Polysulphate is a naturally occurring mineral. It is sustainably mined from deposits of polyhalite in the UK by ICL. Because Polysulphate is simply mined, crushed, and screened with no chemical processing, it offers a low-carbon, environmentally responsible option for growers seeking both sustainability and efficiency.

With its low salt index and low-chloride potassium, it’s safe for both soils and roots and is OMRI Listed for organic use. Its naturally gradual-release profile allows for better nutrient-use efficiency and fewer applications.

How to Use Polysulphate to Strengthen Your Potato Fertility Program

Plan Your Potato Nutrition with Confidence 

In a market where every input dollar must deliver measurable returns, Polysulphate offers a practical way to go beyond NPK—enhancing both performance and sustainability. It’s a versatile, season-long nutrient solution that helps potatoes reach their full potential for yield and quality. 

Learn how Polysulphate can fit into your fertility program. Connect with an expert today.

FAQs 

1. What nutrients does Polysulphate provide for potato crops?

Polysulphate delivers sulfate-based sulfur, potassium, magnesium, and calcium in one low-salt, low-chloride granule.

2. How does Polysulphate improve potato yield and quality?

Its gradual nutrient release supports uniform growth, enhances nitrogen-use efficiency, improves tuber uniformity, and reduces issues like hollow heart.

3. What field trial results support Polysulphate’s performance?

North American trials have shown yield increases from 4.3% to 77%, along with reduced hollow heart and better fry quality.

4. Why are calcium and magnesium important for potato production?

Calcium strengthens tuber structure and reduces defects, while magnesium drives photosynthesis and starch formation that support yield and dry matter.

5. Is Polysulphate considered a sustainable fertilizer option?

Yes. It is a naturally mined mineral with no chemical processing, a low carbon footprint, a low salt index, and OMRI Listed status for organic use.