In 2025, SUL4R-PLUS partnered with Tunley Environmental to measure SUL4R-PLUS carbon footprint.

What is a carbon footprint?

Greenhouse gas emissions are commonly created when fuel and energy are used to power things. For example, burning fossil fuels such as coal, natural gas, or gasoline to create heat, electricity, and fuel vehicles leads to greenhouse gas emissions. A carbon footprint describes the amount of greenhouse gases that are created when things are manufactured. A carbon footprint can generally be broken into three stages:

• Raw Material Extraction: this includes all the greenhouse gases created to harvest ingredients from their sources.
• Raw Material Acquisition: this includes all the greenhouse gases created during the transport of ingredients from their sources to the point of production.
• Manufacturing: this includes all the greenhouse gases that are created during production.

What is SUL4R-PLUS carbon footprint and how does it compare to other fertilizers?

Compared to a dozen other commonly used fertilizers, SUL4R-PLUS has the third lowest carbon footprint (Figure 1). Of these, SUL4R-PLUS carbon footprint is 34% – 81% less than the ten fertilizers that have a greater carbon footprint.

It’s also important to recognize that each fertilizer’s carbon footprint is unique because they each require different ingredients and processes to create the final product. For SUL4R-PLUS, more than 60% of its carbon footprint comes from creating its main ingredient: flue gas desulfurization gypsum.

Flue gas desulfurization gypsum, or FGD gypsum, is a waste product created when coal-fired power plants scrub sulfur-based gases from smokestacks. Per federal regulations, these sulfur-based gases must be scrubbed out of smokestack exhaust to prevent harmful environmental effects like acid rain. Even if SUL4R-PLUS was not on the market, the FGD gypsum would still be produced and would keep creating greenhouse gas emissions to keep the smokestacks free of sulfur oxide gases.

SUL4R-PLUS makes use of this waste product and turns it into a valuable plant-available nutrient source that can enhance crop growth and productivity. Learn more about our Research and the impact that SUL4R-PLUS can have on a variety of crop yields.

Table 1: Citations to the data referenced in Figure 1.

Fertilizer	Citation	Reference in Text
SUL4R-PLUS	Tunley Environmental, 2025	Table 2, page 9
Ammonium Sulfate
Ammonium Nitrate	Fertilizers Europe, 2018	Table 6, page 13
Calcium Ammonium Nitrate		Table 8, page 15
Urea		Table 10, page 17
UAN 30		Table 12, page 19
Ammonium Nitrosulfate	Bretrup and Hoxha, 2016	Table 3, page 5
Calcium Nitrate
Diammonium Phosphate
NPK (15-15-15)
Triple Super Phosphate
Muriate of Potash
Anhydrous Ammonia	Liu et al., 2020	Figure 4, page 7

Here’s a few similar resources we think you may find interesting.

• 

  Weathering the Storm with Consistency

  By now you’re most likely aware of current global fertilizer trends, as spikes in pricing and decrease in supply have affected the whole industry. You also know that fertilizers provide crops with the nutrients they need to grow their best, making them essential to the world’s food supply. We know that the last thing you need is more uncertainty in your day-to-day.

  Read More
• 

  The Top 3 Nutrients Missing from Your Soil Test

  Soil testing can be expensive, and if you’re not sure what kind of testing is most valuable to you, it’s tempting to just choose the most affordable option.

  Read More
• 

  Calcium Clarified: The Basics

  Optimal crop nutrition is more than just N, P and K. Secondary nutrients, like calcium, are often overlooked, but actually serve important roles in crop production.

  Read More