Agriculture Resource Dive: Synthetic Mineral Salts

What Are Synthetic Mineral Salts

As companies that work in the food and agriculture industry, all of us immediately take on the responsibility of ensuring that we’re leaving the food system in a better state than it was before we entered it. In order to do that, one of things we need to do is make sure that we’re informed about the abundant options of agriculture inputs that are out there. Once we have a holistic idea of what exists, only then can the controlled environment agriculture (CEA) operater choose the best option that aligns with their respective principles.

This week, we dive into the grandfather of commercial agriculture: synthetic mineral salts

What Are Synthetic Mineral Salts
Synthetic mineral salts go by a few names, such as mineral fertilizers, mineral salts, synthetic fertilizers, as well as chemical fertilizers. As some of its names suggest, it’s not completely made up of natural compounds. It’s also worth noting that synthetic mineral salts are not the same as the likes of table salt or sodium chloride. 

When used for the purpose of agriculture, synthetic mineral salts will react to water used to grow a plant and release its ionic nutrients, such as commonly used calcium nitrate and potassium phosphate. These are ionic compounds that plants love because it provides the necessary nutrients that it needs to grow. Compared to organic fertilizers, synthetic mineral salts don’t need microbes or bacteria to mineralize or breakdown nutritional compounds in order to turn them into plant-available elements. In fact, plants don’t know the difference between organic and inorganic elements or plant food. What they’re focused on is getting access to the plant available (ionic) form of whatever nutrients are provided to them. 

Where Do Synthetic Mineral Salts Come From
Synthetic mineral salts are produced from a greenhouse gas emissions intensive chemical process, hence why they’re often referred to as chemical fertilizers. A great example is potash mining - performed through underground mining or through solution mining, which is the removal of a soluble mineral by dissolving it and leaching it out. For the underground operations, these potash deposits are born from evaporated sea beds. Fertilizer companies will use boring machines to dig out the ore and transfer the potash to the processing mill above the ground. Here, the raw ore is crushed and refined to extract the potassium salts.

The video below by the third largest potash producer in the world, Nutrien, gives a clear visual explanation of the process.

Potash mining Nutrien

At the moment, the largest amounts of synthetic mineral salts come from Russia, China, Morocco, and Canada. The image below breaks down Brazil’s synthetic mineral salt imports. As one of the biggest agriculture hubs in the world, take note of the origins of its imports which summarizes very well where most synthetic mineral salts are mined.

Mineral fertilizer source by country

Strengths of Synthetic Mineral Salts
Where organic fertilizers rely on the mineralization process to release their plant-available source of nutrients, synthetic mineral salts do not need to rely on it. Soil has a complex and elaborate ecology consisting of bacteria, fungi, protozoa and insects. These organisms use the larger organic compounds found naturally in soil and organic amendments as a source of food. When these organisms “eat” the organic material, the breakdown of the material releases ions that plants can use as food, hence “mineralization”. Synthetic mineral salts are efficient and consistent in formulation as they are not dependent on the aforementioned mineralization of organic material and do not vary based on the soil environment in which they are applied.

When it comes to the sustainable aspect of synthetic mineral fertilizers, some of the largest producers have taken action to shift the industry through the likes of blue ammonia, which produces ammonia with corresponding CO2 byproduct removed through carbon capture and sequestration. There has also been a rise of green ammonia projects such as CF Industries’ construction of North America’s first commercial scale green ammonia project has commenced. Green ammonia is made with hydrogen that comes from water electrolysis powered by alternative energy.

Challenges of Synthetic Mineral Salts
Supply chain issues have been an issue that every farmer around the world has been feeling. China’s urea exports remain low due to government measures to promote domestic availability and affordability, while Russia’s ammonia exports in 2022 are substantially lower than prior years due to Russia’s invasion of Ukraine. Furthermore, political instabilities have led to global sanctions which impact how synthetic mineral fertilizer is supplied to the rest of the world.

CF Industries China Fertilizer Production

To mitigate this, on March 11, the U.S. Department of Agriculture (USDA) announced its support of additional fertilizer production for American farmers to address rising costs and supply chain issues. As such, the USDA has now opened up $250 million worth of funds through a new grant program to support independent, innovative, and sustainable American fertilizer production.

From a health and nutrition perspective, nitrogen, when forcibly fed to plants, promotes rapid and potentially excessive plant growth. In many ways, its similar to giving a human steroids. Nitrogen is the one of the most key types of synthetic mineral salts within commercial agriculture. It rapidly gives the appearance of lush green growth when applied on a lawn. However, its excessive application actually severely harms flora and fauna. They exist for a long time in the soil, atmosphere and waterways, particularly for controlled environment production areas. They can negatively influence soil, other organisms, human health and the environment due to nitrate toxicity, amongst other adverse consequences if the nitrate levels do not dissipate over time. As a result of the synthetic mineral salts, industrial chemicals, trace metals and urban waste enter the soil through disposal of wastewater for both indoor and soil-based farms. As many of us knows, indoor farms are subject to major flushing of their water reservoirs where the synthetic mineral salts sit. When these excessive nitrate levels are retained by the soil, synthetic mineral salts then become responsible for decreasing the soil biodiversity and fertility.

By Riyana Razalee