MicroEssentials SZ from MOS - sulfur plus zinc in one granule for US corn acres

By Julian Reed, ad hoc news Accessories & Components Desk. Reviewed July 01, 2026, 1:20 AM ET. Details in the imprint.

MicroEssentials SZ from MOS crunches under your boots like dry gravel when you walk a Midwestern field in April, each beige granule holding nitrogen, phosphorus, sulfur, and zinc in a single speck. That pre-plant pass decides a lot about how tall your corn will stand in August. Mosaic’s flagship sulfur-plus-zinc blend is quietly becoming standard kit on many high-yield acres across the Corn Belt.

What MicroEssentials SZ actually is

MicroEssentials SZ is a granular phosphate fertilizer that combines 12 percent nitrogen, 40 percent phosphate, 10 percent sulfur, and 1 percent zinc, with sulfur supplied in both sulfate and elemental forms. Each individual granule is formulated to carry that full nutrient stack, rather than splitting nutrients into different products.

The brand is part of Mosaic’s MicroEssentials line, which includes variants like MicroEssentials S10 and S15 with different sulfur profiles. The SZ version specifically targets fields where both sulfur and zinc deficiencies are limiting yield, particularly on lighter soils and in cool, wet springs common in the Upper Midwest.

How the fused-nutrient granule works in the field

The company’s patented Fusion technology binds nutrients together in a single granule so that when a grower runs a strip-till rig or spreader, every plant row should see a similar nutrient mix in the root zone. Agronomists like Mosaic’s Dr. Ron Olson argue this reduces what farmers call “hot and cold” streaks in a field, where some plants get plenty of phosphorus and others miss out.

Because sulfur is present in two forms, sulfate is available immediately for early-season uptake, while elemental sulfur oxidizes over time to feed the crop later in the season. That staggered release matters more as air gets cleaner; atmospheric sulfur deposition has fallen sharply in North America over the past two decades, leaving many farms short and increasing the value of applied sulfur.

US availability, pricing, and use cases

MicroEssentials SZ is widely distributed through US ag retailers, with Mosaic highlighting strong adoption in states like Iowa, Minnesota, and Illinois. In practice, most growers buy through local co-ops or chains such as Nutrien Ag Solutions or Helena Agri-Enterprises at locally negotiated prices tied to global phosphate markets.

Public price sheets show recent MicroEssentials SZ offers in the US Midwest in the rough range of 750 to 900 dollars per ton, though actual transaction prices vary week to week with fertilizer benchmarks and freight. Many farmers team the product with urea ammonium nitrate (UAN) or anhydrous ammonia for additional nitrogen, using SZ to cover the phosphorus, sulfur, and zinc side of the equation.

Why sulfur and zinc matter more now

One driver behind MicroEssentials SZ uptake is that older assumptions about “free” sulfur in rainfall no longer hold. EPA emissions rules slashed sulfur dioxide output from power plants, which has sharply reduced sulfur deposition on cropland. University soil labs now regularly report sulfur deficiencies in corn, canola, and wheat tissues in regions that rarely saw them 25 years ago.

Zinc, meanwhile, is often deficient in high-pH and eroded topsoils and plays an outsized role in early root development and enzyme systems in corn. Mosaic and independent agronomists cite multi-bushel corn yield responses where zinc was added to deficient fields, especially in cool, wet springs that slow root exploration.

Field performance data and farmer experiences

In multi-year on-farm trials summarized by Mosaic, MicroEssentials SZ delivered an average corn yield increase of around five bushels per acre over standard MAP or DAP programs when sulfur and zinc were limiting. Third-party strip plots run by land-grant universities show similar magnitudes in responsive environments, though results flatten in well-fertilized fields.

A Nebraska grower quoted in industry outlet AgWeb described switching to SZ after seeing pale corn on sandier ridges despite adequate nitrogen. After the change, tissue samples showed higher sulfur and zinc levels in V5 corn, and the grower reported more uniform canopy color by tassel stage, though yield benefits varied by year.

Trade-offs versus conventional phosphate

Compared to diammonium phosphate (DAP) and monoammonium phosphate (MAP), MicroEssentials SZ carries a premium because of the added sulfur, zinc, and processing cost. That makes it harder to justify on deep, high-organic-matter soils with robust historical manure applications where sulfur and zinc are already adequate.

Some independent agronomists suggest that on non-deficient soils, simply broadcasting SZ for “insurance” can erode margins compared to cheaper MAP plus targeted zinc and sulfur where soil tests show need. Others, including Mosaic agronomy director Mike Berry, counter that field variability and the risk of underestimating sulfur demand make a simple blended solution attractive, especially on rented ground where soil-test history is thin.

Environmental and operational considerations

From an environmental angle, sulfur in SZ is not a regulatory focus the way nitrogen runoff is, but phosphorus losses to water remain under scrutiny in the Mississippi River Basin and Lake Erie watersheds. Because SZ is a granule, not a liquid, it does not inherently reduce runoff risk versus MAP or DAP, so standard 4R nutrient stewardship guidelines still apply.

Operationally, retailers like that SZ handles much like MAP in the tower and in spreaders, which means no special equipment is required. The uniform granule size helps maintain an even spread pattern at wide boom widths, something co-op managers in trade interviews say matters more as spreaders move from 60-foot to 90-foot and beyond.

Where MicroEssentials SZ fits in Mosaic’s portfolio

MicroEssentials SZ sits alongside Mosaic’s flagship phosphate products and its Aspire potash line, which combines potassium with boron in a similar fused granule. The company positions these value-added fertilizers as a way to differentiate beyond basic commodities and capture a per-ton premium.

In its latest annual report, Mosaic highlighted growth in premium product volumes, including MicroEssentials, even as overall fertilizer markets cycled down from the 2022 spike. CEO Bruce Bodine has repeatedly flagged MicroEssentials as a focus area for innovation and margin resilience on earnings calls, describing the line as a "technology platform" rather than just another NPK blend.

Mosaic context and investor view

Mosaic is one of the largest integrated producers of phosphate and potash fertilizers globally, with mining and processing assets in North America and South America. MicroEssentials SZ is a relatively small slice of total tons, but it sits in a segment where Mosaic can flex pricing power and agronomic branding more than on generic DAP.

Mosaic stock (NYSE: MOS, ISIN US61945C1036) gives US investors direct exposure to that value-added fertilizer story, though MicroEssentials is just one component of a portfolio still dominated by bulk phosphates and potash.

This article was AI-assisted and editorially reviewed. Product information is provided without warranty; prices and availability may change at short notice. Not investment advice and not a buy or sell recommendation. Securities trading carries risks up to total loss.