Sulfur (S) is an important plant nutrient essential to produce healthy plants with high yields. No matter the crop, fruit, vegetables, grains, or pasture crops, they all need sulfur to reach their full yield potential. This important secondary macronutrient plays a role in soil health and fertility, contributing to the overall sustainability of agricultural ecosystems.
Why has the need for sulfur inputs increased across the US?
In the past, sulfur deficiency wasn’t a major concern for growers across the US due to ample supplies from organic matter and sulfur emissions. Industrial processes provided much of plants’ sulfur needs through atmospheric release. Yet, in the last three decades, recent legislation aimed at improving air quality has reduced sulfur emissions and drastically lowered atmospheric sulfur availability in North America. Coupled with increased crop productivity leading to higher sulfur uptake during harvest, both visible and hidden sulfur deficiencies are now more common in many regions. With agriculture’s expanding scale depleting soil sulfur further, the demand for sulfur and sulfate-based fertilizers has grown.
What is the role of Sulfur in plant development?
Adequate sulfur levels in soil promote optimal crop growth, development, and yield. Sulfur is essential for:
- Protein formation & synthesis: Sulfur is need for plants to form proteins, enzymes, vitamins, and chlorophyll. In legumes, it is crucial in nodule development and efficient nitrogen fixation. Protein synthesis requires large amounts of sulfur, especially for the formation of oils within the seed. As a constituent of several amino acids and vitamins found in plants and animals, sulfur is critical for determining the nutritional quality of foods.
- Photosynthesis: Sulfur is also essential for photosynthesis and contributes to crop winter hardiness.
- Nutrient Balance: Sulfur interacts with other essential nutrients like nitrogen, phosphorus, and potassium, influencing their availability and uptake by plants. Maintaining a balanced nutrient profile, including sulfur, is crucial for maximizing crop productivity and quality. In fact, an adequate supply of sulfur is crucial, not only for crops with high sulfur requirements – such as legumes (alfalfa, clover, soybean, etc.) and Cruciferae (canola and rapeseed) – but also for crops with high nitrogen requirements (maize and cotton), which require sulfur to optimize their nitrogen utilization.
- Yield and Quality Improvement: Adequate sulfur levels in soil promote optimal crop growth, development, and yield. Sulfur deficiency can result in reduced crop yields, poor quality produce, and increased susceptibility to pests and diseases.
Symptoms of Sulfur Deficiency
Pale green leaves, starting first on younger leaves, indicate sulfur deficiency. Eventually, the whole plant will have a light yellow-green appearance. Plants displaying sulfur deficiency often appear smaller with stunted growth. Learn more about sulfur deficiency here!
What is elemental sulfur vs sulfate?
Elemental sulfur requires microbial oxidation to convert into sulfate form before it can be utilized by plants, while sulfate-based fertilizers provide sulfur in the immediately available sulfate form. Sulfate-based forms are more readily available to the crop, but also prone to leaching in high rainfall environments, unless available in gradual release forms. The choice between the two often depends on factors such as soil conditions, crop requirements, and application timing preferences.
Why is Polysulphate (polyhalite) considered a superior form of sulfur?
Being a naturally occurring sulfate-based multi-nutrient, polyhalite, Polysulphate is plant-available, releases gradually and contains four essential nutrients. It doesn’t require chemical separation or industrial processing and provides a steady supply of easily absorbed nutrients. The season-long release aligns with peak plant demand, enhancing nutrient use efficiency and reducing leaching risks. Not only does Polysulphate provide sulfate-based sulfur, it also provides magnesium, calcium and low-chloride potassium. In field trials and third-party research it has been proven to effectively improve yield and quality across a wide range of crops and soil types. With its low chloride and salt index, neutral pH, and absence of liming effects, OMRI-approved Polysulphate is a safe option even for sensitive crops.
6 Brands found

The perfect controlled release solution for precision crop nutrition
Agroblen® Total controlled release fertilizers are designed to deliver precision crop nutrition that can be matched to your specific crop, stage of growth, climate and overall nutritional program to maximize yields. Agroblen® uses ICL’s patented Resin Release Technology that precisely controls the release of nutrients. The release is regulated by soil temperature and ensures that the nutrient availability closely matches plant demand. This reduces the excess of nutrients that is lost into the atmosphere or soil, which means it minimizes the fertilizer’s environmental impact. As a result, this technology maximizes your crops’ uptake and nutrition use. The proven performance of Agroblen® Total provides growers with unmatched nutritional options to meet the needs of their specific crops and growing conditions.
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State-of-the-art nutrition giving you higher Nutrient Use Efficiency (NUE) with fewer applications
Agrocote® sets the standard in efficient precision fertilization. The 100% individually N, P or K coated granules give you a continuous release of nutrients in a controlled manner. You’ll see the benefits of this breakthrough in precision nutrition reflected in higher crop yields. It’s both highly effective and exceptionally practical to use and easy to apply. Agrocote® also helps you reduce your environmental impact by limiting nutrient losses due to leaching, volatilization, denitrification and P-fixation. Agrocote® brings all the benefits of controlled-release plant nutrition to your fields.
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Strengthen your roots and maximize your yield to full potential with CHALLENGE
CHALLENGE is a premium “root builder” designed to enhance root development, nutrient uptake, and overall plant health. Combining high-quality, pharmaceutical-grade potassium-tri-poly phosphate (KTPP) with organic acids, CHALLENGE ensures optimal availability of potassium and phosphorus to the plant. Its pH-neutral formula is compatible with most pesticides, making it versatile for foliar, soil, drip, and transplant applications. CHALLENGE provides a proven, flexible solution to enhance crop performance and support quality yields.
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The power of Polysulphate with a boost of phosphorus and potassium for season-long nutrition
ICL PKpluS®: Your Complete 5-in-1 Fertilizer Solution for High-Performance Crop Nutrition ICL PKpluS® is a premium line of PK fertilizers plus Polysulphate, designed to provide a single solution for granular crop nutrition. ICL PKpluS delivers five essential nutrients—phosphorus, potassium, sulfur, magnesium, and calcium— all in one convenient application. This advanced fertilizer formulation ensures a steady, controlled release of nutrients over an extended period, optimizing nutrient delivery throughout the growing season for a wide range of crops. By applying ICL PKpluS, farmers can efficiently supply key nutrients such as phosphorus and potassium, along with sulfur, magnesium, and calcium, in a single product. This streamlined approach reduces the need for multiple applications, saving both time and effort.
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The groundbreaking total range of water-soluble straight and liquid fertilizers
You need pure, clean fertilizers to grow your crops safely. Nova provides the solution. The Nova line of water-soluble straight and liquid fertilizers offers a comprehensive portfolio of unique, highly soluble fertilizers specially selected for fertigation and foliar application. Offering growers a superior selection of single-source fertilizers essential to healthy and productive crop growth, at every stage, Nova fertilizers are a highly efficient, fast-dissolving, and 100% water-soluble source of essential NPK plant nutrients. Select Nova formulations are also available in concentrated liquid form for added flexibility and versatility! Derived from an unrivalled quality source, you can mix it with other straight or compound fertilizers, such as Agrolution, for maximum performance. Available as safe powder-blend fertilizers, and now in concentrated liquid form, precise formulations effectively deliver the nutrients required for optimum growth, yield, and quality. Highly pure, fully chelated, and fully soluble, nutrients quickly dissolve with no risk of clogging irrigation systems and are easily and safely blended, stored, and handled.
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The four-in-one natural fertilizer
What is Polysulphate (polyhalite)? Made by nature, mined by ICL. Polysulphate® is a naturally occurring mineral fertilizer, polyhalite, mined exclusively by ICL. Available as a granule, sphere, or powder, it is soluble, plant-available, and easy to blend and spread, making it a cost-effective sulfur solution. Deposited in the earth 260 million years ago, each Polysulphate granule naturally contains Sulfur, Potassium, Calcium and Magnesium – four of the six essential macro-nutrients required for optimal plant growth. Since 2010, hundreds of field trials have been conducted worldwide demonstrating Polysulphate’s efficacy in improving both crop yield and quality. Why is Polysulphate more effective than other forms of sulfur? Polysulphate—a better source of Sulfur As a naturally occurring sulfate-based multi-nutrient, polyhalite, Polysulphate requires no chemical separation or industrial processing, delivering high agronomic value for low environmental impact. Providing a season-long source of plant-available nutrients, Polysulphate’s gradual release pattern safely meets peak plant demand and improves nutrient use efficiency while reducing risks of leaching. It is proven to produce a healthier and more productive crop across a wide variety of soil types. Low-chloride, low salt index, neutral pH and no liming effect make it a safe choice even for sensitive crops. Natural, certified-organic, low carbon footprint. Polysulphate is a natural product with a low carbon footprint, licensed for use in organic farming systems. Polysulphate sets the standard in environmental sustainability among fertilizers, with Polysulphate Standard, and Granular having the the lowest carbon footprint (compared to similar products) of just 0.0029 kilograms of CO2 equivalent per kilogram of product. Polysulphate is suitable for organic farming systems and is approved for organic use by several certification agencies around the world, including Ecocert, Ceres, and OMRI.
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