Before delving into the big four fertilizer macro-nutrients – nitrogen (N), phosphorus (P), potassium (K) and sulfur (S) – I’ll address a trace element that often gets under-publicized: zinc.

In his “Eco-farm,” Charles Walters wrote, “Zinc is only now [1996] joining the crowd of elements required for healthy plant production in the conventional lexicon. Up till very recently, agronomists couldn’t agree on its function, except to note that certain weed patterns appeared when zinc disappeared. Plants do require it in the 3 to 100 ppm range [in soils].”

Fast forward to the April 3, 2025, Andersons’ online newsletter (at andersonsplantnutrient.com/agriculture/market-feed/5087), where their company research agronomist Bethany Widman wrote, “Zinc might be a micronutrient, but its impact is massive. Deficiencies can shrink your yields before you even see the signs. To maximize yields at harvest and defeat deficiencies, be sure to provide this season’s crops with proper nutrition throughout the growing season.”

Widman noted that one of zinc’s biggest roles is cell elongation within crops, a process driving root expansion and plant height. Stronger, deeper roots mean better access to nutrients and water, especially crucial during dry conditions. Improved root growth provides plants better nutrient and water uptakes.

This is critical in dry growing conditions, when plant roots need to expand their influence in soil to find moisture. As cells elongate, surface area of plant leaves also increases. Leaves are like miniature solar panels – as they enlarge, the plant absorbs more sunlight, increasing photosynthesis.

Every soil lab I work with tests for zinc. The most common form of zinc I recommend as a soil amendment is zinc sulfate, which is approximately 36% elemental zinc. If you want to apply 3 lbs. of actual zinc/acre, you need to put down 8.33 lbs. zinc sulfate.

Zinc may also be presented to plants in chelated form, which increases the element’s biological availability. Chelation costs more, an expense which many growers believe is well repaid by increased crop performance.

Zinc naturally exists in the soil from rocks, parent material and organic matter. However, naturally occurring zinc tends to get tied up in the soil due to high pH and low organic matter, making crops deficient. Zinc deficiencies are commonly detected early in growing seasons in cool, wet soils. This is due to slow natural release of zinc from organic matter.

Zinc can also become deficient in high-P soils. High P levels can retard zinc uptake, thus making this mineral unavailable to crops when it’s needed most. This interaction is especially evident in grass crops like corn. Very few Northeast soils are naturally high in P.

Moving on to the “big four,” I tap into to the expertise of Jeff Cassim, general manager of Liquid Products in Seneca Falls. Cassim extracts data from fertilizer industry periodicals, not just commodity prices, but geopolitical facts impacting energy commodities as well as plant food raw materials. These are average values calculated from a range of dollar costs per short ton for the day of the quote, May 15, 2025. The location of the quote is the freight point-of-origin nearest the Northeast. In parentheses is that commodity’s year earlier (5/15/2024) price. In brackets is the percentage of change for the ingredient in question from 2/13/2025 to 5/15/2025.

Urea (Cincinnati) $603 ($373) [+32.5%]; ammonium nitrate (Mid-South) $380 ($335) [+13.4%]; ammonium sulfate (Minneapolis) $485 ($438) [+1.5%]; urea/ammonium nitrate (Cincinnati) $403 ($268) [+24.8%]; ammonia (Eastern Corn Belt) $638 ($608) [+4.9%]; diammonium phosphate (DAP) (Cincinnati) $720 ($643) [+12%]; mono-ammonium phosphate (MAP) $713 ($640) [+10%]; muriate of potash (Vancouver) $291 ($229) [+11.9%]; sulfate of potash (West Coast) $695 ($645) [+14.3%]; and sulfur (Gulf Coast) $265 ($88) [+54.1%].

According to Cassim’s sources, cooler than usual weather should return to the Northern Plains and Corn Belt toward the end of May, while chances for precipitation are expected to drop for much of the U.S.

The National Weather Service (NWS) forecasts cooler than usual temperatures are expected for the Great Lakes and Northeast approaching May’s end. NWS expects below average to near normal precipitation across much of the country, while above average rainfall is expected for Appalachia and the Northeast.

Phosphate prices increased week-over-week due to higher barge sales and are only expected to rise further in the coming weeks. Meanwhile, buyers tread the market carefully to meet anticipated fall demand, due to concerns regarding future phosphate availability. Any concerns related to inventory carrying costs over summer will likely be tempered by uncertainty regarding future supply options.

In the N arena, the New Orleans (NOLA) market center reacts to news that China has committed, starting in June, to exporting 2 million metric tons of urea. Volumes of this ingredient from China entering the global market won’t impact NOLA directly, but will likely defuse some of the existing market-wide urgency to build up summer inventories. Chinese exports could also cause traders to direct other urea volumes to the U.S.

For urea shipments originating at NOLA, expected delivery times upriver stretch into spring season, a period when demand typically starts softening. Such an expectation has already taken prices at the port down from the 2.5-year highs seen earlier in May. But traders expect top-dress demand to emerge in the next few days, which occurrence should limit the extent to which prices drop for promptly loaded barges at NOLA.

Meanwhile, the history (as well as the present) of the U.S.-spawned international tariff drama is anything but boring. The impact on the April 2 tariffs on U.S. fertilizer prices was immediate, with NOLA barge prices for urea and DAP jumping sharply on April 3. At that time, Bloomberg (Market) Intelligence Analyst Alexis Maxwell stated that U.S. corn farmers could expect to see fertilizer expenses rise 3% – 7% in response to tariffs.

In the intervening weeks the global tariff placement/removal seesaw game causes instability that stock markets detest. This applies to much more than fertilizer. Making things even more interesting, as of May 20, Japan began demanding that U.S. eliminate tariffs on Japanese imports.