At Phospholutions, we believe that our global food system demands better solutions for sustainable production and responsible use of phosphorus. We develop innovative nutrient use efficiency technologies and through partnerships with global fertilizer manufacturers, retailers and growers advance sustainable fertilizer technology.
Unearthing the Phosphorus Treasure Trove
Phosphorus, a vital nutrient for plant life, underpins agricultural production and global food security. But where does this essential element come from? The answer lies in a seemingly unremarkable rock called phosphorus rock, or phosphorite.
Phosphate rock is a sedimentary rock formed over millions of years. Ancient marine animals, rich in calcium and phosphorus, accumulated on the seabed. Over time, geological processes like compaction and lithification transformed these deposits into rock strata. Today, these phosphate deposits exist in sedimentary basins around the world.
Global Phosphorus Reserves
Efficiently using global phosphate reserves extends the life of the mines furthering the sustainability of this important resource. Some of the major countries boasting significant phosphate rock reserves include:
Norway is the recent leader in phosphate reserves discovering 71 billion tons in 2018.1
Morocco claimed about 71% of the world’s phosphate reserves prior to the discovery in Norway. Its phosphate rock reserves come in at 50,000 billion tons, now about 40% of global reserves.2
Egypt lands in the third spot with 2,800 billion metric tons.
China distantly follows Morocco in reserves but leads global mining production with 90 million metric tons in 2023.Common estimations say the world has 300-400 years of global phosphorus reserves.
United States Phosphorus Production
Today, the U.S. produces about 88% of the phosphate rock domestically consumed. The U.S. phosphate reserves are sitting at about 1 billion metric tons or 1.3 or world reserves. The United States’ significant phosphate rock deposits are primarily concentrated in Florida and North Carolina.
Phosphate rock mining utilizes various techniques depending on the deposit's location and characteristics. Here's a glimpse into some common methods:
Surface mining: This method is employed for near-surface deposits. Large excavators remove overburden (layers of soil and rock) to expose the phosphate rock, which is then extracted and transported.
Underground mining: For deeper deposits, underground mining techniques like shaft mining and room and pillar methods are used. These methods involve creating access tunnels and extracting the rock from underground chambers.
Dredging: In some cases, phosphate rock deposits may be located underwater on continental shelves. Here, dredging ships equipped with powerful suction devices extract the rock from the seabed.
Kyle Isaacson, Ph.D. and Formulation Scientist at Phospholutions, says there is plenty of room for improvement in the process.“
"Expanding phosphorus production not only harms the environment but also incurs higher costs compared to optimizing the resources we currently mine. Once extracted, the phosphate rock undergoes a series of processing steps to remove impurities and improve its fertilizer value. These processes may involve crushing, grinding, washing, and flotation to separate the phosphate minerals from unwanted materials.
“There is considerable waste in the system.” Isaacson says. “To produce about one ton of phosphate fertilizer, there are about four tons of waste called phosphogypsum that are unusable in the U.S. due to the heavy metal and radioactive content. “
In 2022, phosphate rock was mined by five companies at nine mines in four states. Efficiently using the mines we have is much more cost effective than remediating abandoned mines or opening new ones.
From Rock to Plant Food: The Birth of MAP and DAP Fertilizers
Phosphate rock, in its raw form, isn't readily available to plants. To unlock its potential, it needs to be converted into more soluble forms that plants can easily absorb. This is where the evolution of fertilizer technology comes into play.
The Transformation into MAP (Monoammonium Phosphate):
Reaction with Sulfuric Acid: Ground phosphate rock is treated with sulfuric acid (H2SO4) in a controlled environment. This reaction produces phosphoric acid (H3PO4), a key intermediate.
Neutralization with Ammonia: During the granulation process, the phosphoric acid is then neutralized with ammonia (NH3) to create monoammonium phosphate (NH4H2PO4), also known as MAP.
The Creation of DAP (Diammonium Phosphate):
Reaction with Sulfuric Acid: Ground phosphate rock is treated with sulfuric acid (H2SO4) in a controlled environment. This reaction produces phosphoric acid (H3PO4), a key intermediate.
Neutralization with Ammonia: During the granulation process, the phosphoric acid is then neutralized with ammonia (NH3) to create monoammonium phosphate (NH4H2PO4), also known as MAP.
Both MAP and DAP are highly soluble fertilizers, readily taken up by plant roots. They provide a valuable source of phosphorus, promoting plant growth, root development, and crop yield.
Isaacson says MAP and DAP are in fact perhaps too soluble. “MAP and DAP release their phosphorus within about one month and it is well understood that phosphorus binds tightly to the soil and is immobile. Although phosphorus deficiencies show themselves early in the growing season, uptake of P needs to be constant throughout the season.”
So how do we efficiently use these phosphate reserves and improve plant use efficiency?
The Future of Phosphorus Rock
Phosphate rock is a finite resource, and concerns exist regarding geopolitical matters – who has phosphate reserves and is willing to trade with who. Exploration for new deposits, improved mining practices, and alternative phosphorus sources are crucial for ensuring maximum crop yields and long-term food security. Additionally, improving fertilizer application techniques to minimize waste and maximizing phosphorus use efficiency are essential steps towards preserving domestic phosphate reserves.
The Next Generation of Phosphorus Fertilizer — RhizoSorb®
It’s advantageous for the U.S. to make the most of the domestic reserves we have left. RhizoSorb from Phospholutions increases phosphate efficiency up to 50% and makes an impactful contribution to having a more sustainable system.” says Isaacson. Phospholutions is applying advancements in soil science and nutrient technology to bring a new age phosphorus fertilizer to market called RhizoSorb.
RhizoSorb is a granular phosphorus fertilizer that has a mined and processed material added to the phosphate rock during the ammonium phosphate production process to improve efficiency.
“RhizoSorb’s patented plant-driven release of phosphate is about 50% more efficient than MAP and DAP”, says Isaacson. “This improvement in efficiency goes a long way in preserving U.S. phosphate reserves and reducing waste products that are difficult to manage.”
A More Efficient Phosphate Fertilizer
RhizoSorb is an economical choice for both growers and retailers. “Compared to using MAP or DAP, growers will apply a little less and see about a 10% cost savings on a per acre basis. Meanwhile, retailers will see about a 20% improvement in margin,” says Craig Dick, VP Sales & Marketing.
RhizoSorb has 38% less salt than MAP/DAP, less product volume applied means reduced storage and handling. Yet with similar physical qualities to MAP/DAP such as pH, angle or repose and hardness, make for a smooth transition into the fertility program.
RhizoSorb provides a win-win. It extends mine reserves and improves the sustainability of phosphorus fertilizer production RhizoSorb increases retailers margin opportunity, and it saves growers money while preserving yield.
Sources:
1. Massive phosphate deposits in Norway could help build batteries and solar panels for 100 years.
2. Reserves of phosphate rock worldwide in 2023, by country.