skip to Main Content

Ammonium Sulfate: Proven to Perform.

Ammonium sulfate (21-0-0-24S) fertilizer delivers pound for pound the most readily available nitrogen and sulfur to the crop, and its high-density form makes it an efficient and versatile fertilizer that consistently delivers ROI by improving plant health and increasing yield.

For over a century, agronomists, advisors, retailers, and growers alike have relied on independent and scientifically backed research to verify the nutrient benefits of ammonium sulfate and other fertilizers. Decades of scientifically proven laboratory, university and field research conducted across multiple crops has consistently shown yield response to ammonium sulfate.

Below are several common questions about ammonium sulfate and how it compares to one of its alternatives.

The Preferred Nutrient Source

Why is nitrogen important to the crop?

  • Nitrogen is an integral part of chlorophyll (key to photosynthesis) and an essential component of amino acids (key to protein formation). Many of those proteins are enzymes, which is critical for plant metabolism.

Why is sulfur important to the crop?

  • Sulfur plays a critical role in early plant stand, contributes significantly to leaf and canopy health, and is a key component of amino acids, proteins and oils. Choosing the right form of sulfur is critical to ensure crops are not short of this necessary nutrient.

Why is ammonium sulfate the preferred source for nitrogen and sulfur?

  • Ammonium sulfate is a product that has consistently maximized crop performance for the benefit of both growers and ag retailers. By providing both readily available ammonium nitrogen and sulfate sulfur to the plant, ammonium sulfate gives growers the ability to time its application around weather events, crop planting and maturity windows with confidence that the fertilizer is effective at delivering for the crops.

Trusted, Reliable, Proven

Is ammonium sulfate proven in the field?

  • Ammonium sulfate has been trusted and relied on for over a century. Why? Through both independent and in-field research it’s been proven to perform across multiple crops and across many geographies and soil types to deliver maximum yield and high-quality crops. It’s the tried and true nitrogen/sulfur fertilizer.

What research has AdvanSix conducted on ammonium sulfate?

  • For over 50 years, AdvanSix has conducted hundreds of replicated research trials across crops with universities and institutes around the world and results have been published in renowned agronomy journals. AdvanSix seeks to grow and raise awareness of sulfur nutrition and ammonium sulfate use across the world.

What are some of the latest crop-related research information pertaining to ammonium sulfate?

  • Research shows that as soybean yield potential increases due to improved genetics, the plant no longer naturally fixes all of the nitrogen it needs to maximize performance at these higher levels. This gap requires new approaches to nutrient management, of which both nitrogen and sulfur can contribute, to enhance ROI for growers.

Pound for Pound Efficiency

What is the nutrient density of ammonium sulfate?

  • With a nutrient density of 45%, the typical ammonium sulfate delivers pound for pound the most readily available nitrogen and sulfur to the crop than other fertilizers. For example, 100 pounds of ammonium sulfate applied per acre delivers 21 pounds of available nitrogen and 24 pounds of available sulfur.

How can ammonium sulfate also help to achieve operational efficiency?

  • The fertilizer industry requires a proven and readily available source of nitrogen and sulfur that offers logistical and crop use efficiencies on the operations side yet offers end users the most density and nutrient availability. The analysis of ammonium sulfate clearly indicates how it can help logistics and application efficiency, because it delivers more nutrient density per pound than any other nitrogen and sulfur fertilizer today.


Why is flexible application important?

  • Growers need to plan around other crops, weather, planting windows and maturities. It’s important to choose a fertilizer that is ready to work when you are.

How does ammonium sulfate incorporate into an existing nutrient program?

  • The multiple formulations and blending compatibility with other dry fertilizer sources make ammonium sulfate a complementary fit to almost any production program requiring nitrogen and sulfur.

When can you apply ammonium sulfate fertilizer to the crop?

  • Because nitrogen and sulfur in ammonium sulfate are immediately available, it can be applied pre-plant through top/sidedress, broadening the window during which growers may make plans for other crops’ life cycles and weather.

Can ammonium sulfate be applied on a variety of crops?

  • Ammonium sulfate is a win-win for retailers because ammonium sulfate applications are not only flexible in terms of timing but suit a wide range of crops and blend spectrum, giving the retailers the best chance of achieving favorable annual bin turns, and in turn improving inventory management and risk mitigation. During seasons where time is of the essence, ammonium sulfate’s nutrient efficiency simply removes various unnecessary logistical issues — less time filling the trucks, refilling spreaders and eliminating the need for additional equipment to haul more product.

Don’t Accept Ammonium Sulfate Alternatives

Because of changing seed genetics, environmental and cropping factors, sulfur nutrition has become more important. Consequently, there are competitors of ammonium sulfate that are promoting unverified features, benefits and agronomic claims. There is still no alternative that is as efficient and economical on a pound for pound basis as ammonium sulfate.

What is an organic-containing ammonium sulfate fertilizer?

  • One alternative to ammonium sulfate is organic-containing ammonium sulfate fertilizer. Such a product has part of its composition derived from plant, animal and or human matter, with the rest comprised of ammonium sulfate. These products are sometimes referred to as “bio-based”.

What is the difference between an organic-containing ammonium sulfate fertilizer and traditional ammonium sulfate fertilizer?

  • Ammonium sulfate has a nutrient density of 45% and delivers readily available nitrogen and sulfur nutrition to crops, while some organic-containing ammonium sulfate fertilizers, such as SymTRX™ 20S, contain only 37% nutrient density, delivering approximately 20% less nutrition to crops per pound of fertilizer applied.

Organic-containing ammonium sulfate fertilizers are typically comprised of 80% ammonium sulfate synthetic fertilizer. In addition, roughly 90% of the nitrogen and sulfur content is chemically derived from ammonia and sulfuric acid.

What is one of the most common ways to increase organic matter levels?

  • Manure is known as a great soil amendment and is often applied in areas with livestock. Conservation practices can leave more plant residue which increases organic matter.

A typical application of an organic-containing ammonium sulfate fertilizer will add a mere 16 lbs. of organic matter per acre compared to over 3,000 lbs. per acre when manure is applied at recommended levels for use as a soil amendment. Using this type of fertilizer results in increases in the organic matter in typical soil by a meager 0.001%, while delivering only approximately 80% of the nutrient density of ammonium sulfate.

Wholesalers, dealers, and growers have to ship, store, and use 20% more organic-containing ammonium sulfate fertilizer to provide the same amount of nutrient and agronomic benefit to the crop as ammonium sulfate.

It takes an entire extra load of organic-containing ammonium sulfate fertilizer to get the same amount of nutrient and agronomic benefit of ammonium sulfate.

Does having organics mean the product is slow release?

  • Independent testing results show certain organic-containing ammonium sulfate fertilizers (e.g., SymTRX™ 20S) have agronomically insignificant slow release benefits and is far more similar to ammonium sulfate than an actual slow release fertilizer.

Soil Incubation Method to Characterize Nitrogen Release Pattern

Adapted from: Medina et al.: Journal of AOAC International Vol. 97, No. 3, 2014; Evaluation of a Soil Incubation Method to Characterize Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers
Back To Top