Phosphorus is an essential mineral that can be found within human bones and teeth, as well as genetic material such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is estimated that around 1% of a person’s total body weight comprises phosphorus.
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Phosphorus is also an essential nutrient in plants, as it allows plants to convert other types of nutrients into usable building blocks to support its growth. As a result of the dependence plants have on phosphorus, this mineral is often incorporated into most fertilizers.
Threats to Phosphorus Sustainability
Over the past 70 years, the use of mineral phosphorus fertilizers has increased significantly to allow farmers worldwide to provide food for people and livestock.
In some parts of the world such as Africa, farmers cannot afford sufficient fertilizers to maintain fertile soils, increasing the likelihood that their crop yield will reduce significantly over time.
In regions throughout Europe, North America, and Southeast Asia, there is excessive use of phosphorus in fertilizers which has threatened the water quality in these areas.
Phosphorus used in fertilizers originates from phosphate rock, which often contains a variety of contaminants such as cadmium that can be transferred to fertilizer products, accumulate in the soil, and eventually end up in food products that will be consumed by the public.
Five countries in the world hold 85% of known phosphorus rock reserves. Therefore, there is a constant threat of geopolitical turmoil to the access of available phosphorus reserves. The vulnerability of phosphorus supplies to these global challenges can prevent farmers from accessing affordable fertilizers that are needed to feed populations around the world.
An additional concerning aspect of phosphorus use in fertilizers is the amount of phosphorus that can be lost to freshwaters. Since phosphorus often attaches itself to soil particles, it can easily move from land to bodies of water via runoff.
Since groundwater typically discharges into surface water, the ability of phosphorus to also flow through these water supplies subsequently threatens the quality of surface water.
Phosphorus loss to surface freshwater can lead to the growth of harmful algal blooms such as microcystis, as well as nuisance algae like cladophora. Furthermore, phosphorus loss can cause environmental degradation through the development of hypoxic or ‘dead’ zones that are not supportive of aquatic life.
The Challenge of Phosphorus Sustainability
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Why Must We Act Now?
The high demand for phosphate by the industrial agricultural sector is expected to deplete current phosphate rock reserves within 20 to 100 years, although this is largely debated by some analysts.
This demand for phosphorus has led phosphate mining processes to easily cause damage to the environment, as well as negatively impact local economies, in their efforts to quickly supply phosphorus to western nations that often inefficiently use this mined resource.
The release of high amounts of phosphorus into water supplies is also polluting lakes, rivers, and oceans around the world.
These factors clearly demonstrate the need to reduce the global dependence on phosphorus.
Recently, the NSF Science and Technology Center, located at the North Carolina State University, has been announced as a national research effort to reduce global phosphorus dependence while also limiting the ability of this mineral to contaminate our essential water supplies.
What is the STEPS Project/NSF Center?
The NSF Science and Technology Center has recently announced its Science and Technologies for Phosphorus Sustainability (STEPS) project. This project is a joint effort between North Carolina State University and eight additional institutions. It is supported by an initial $25 million USD grant that will remain available for five years.
Some of the ambitious goals of the STEP projects include reducing human dependence on mined phosphates by 25%, as well as reducing phosphorus losses to soil and water resources by 25% over the next 25 years.
By achieving these goals, the STEPS project hopes to reduce environmental damage caused by excess phosphorus runoff while simultaneously supporting the independence of the agricultural industry from the unreliable future of phosphorus mining.
How will the STEPS Project Advance Agricultural Solutions?
To achieve these goals, the STEPS project will support the development of materials, technologies, and management practices that will allow farmers worldwide to recover, recycle and reuse phosphorus.
Many of these technologies will focus on capturing phosphorus that is often lost in soils and surface waters, as well as in both human and animal waste. Once this mineral is captured from these sources, it can then be reused and recycled into new fertilizers.
Another aspect of the STEPS project is to incorporate a 50-year phosphorus field trial experiment that has been conducted at Tidewater Research Station in Plymouth, North Carolina. Throughout this experiment, scientists have applied different amounts of phosphorus to crops to determine phosphorus-deficiency resilience, as well as the mechanisms by which phosphorus remains in the soil.
The persistence of phosphorus in these soil deposits, which is otherwise referred to as legacy phosphorus, can be used as a nutrient for plants and subsequently reduce the demand for fertilizers.
References and Further Reading
Bronlie, W. J., Sutton, M. A., Reay, D. S., et al. (2021). Global actions for a sustainable phosphorus future. Nature Food 2; 71-74. doi:10.1038/s43016-021-00232-w.
Phosphorus and water [Online]. Available from: https://www.usgs.gov/special-topic/water-science-school/science/phosphorus-and-water?qt-science_center_objects=0.
Alewell, C., Ringeval, B., Ballabio, C., et al. (2020). Global phosphorus shortage will be aggravated by soil erosion. Nature Communications 11(4546). doi:10.1038/s41467-020-18326-7.
Farmers are facing a phosphorus crisis. The solution starts with soil. [Online]. Available from: https://www.nationalgeographic.com/science/article/farmers-are-facing-a-phosphorus-crisis-the-solution-starts-with-soil.
New NSF Center Will Advance Phosphorus Sustainability. [Online]. Available from: https://news.ncsu.edu/2021/09/new-nsf-center-will-advance-phosphorus-sustainability/.