Rising Interest in Remineralization for Soil Restoration Efforts

This article was co-authored by:

Chris Kozicki
Agglomeration Expert

Carrie Carlson
Technical Writer

Reports of depleted soils and increasingly nutrient-deficient crops have littered headlines in recent years. Scientists around the world are calling for improved management of soils as the effects of long-term misuse become more evident and the struggle to feed a growing population puts agriculture under increasing pressure. While a multi-faceted solution is needed, one technique seems to be gaining traction quickly: remineralization.

Remineralization – the practice of applying rock dust to soil in an effort to mimic nature’s fertilizing process – has become a trending topic in the effort to restore soils. As a result, rising interest around developing rock dust products to restore soils is being seen.

The Concept Behind Remineralization

Remineralization is an age-old concept that the Earth has been carrying out on its own since the beginning of time.

Rocks of different types are made up of varying minerals and combinations thereof. These minerals are liberated from rocks through weathering, naturally increasing the surrounding soil fertility over time.

The concept of speeding up the remineralization process through the application of rock dust to soils has long been understood. In 1894, a book by agricultural chemist Julius Hensel, entitled Bread from Stones: A New and Rational System of Land Fertilization and Physical Regeneration, was published. The publication detailed the concept of remineralization and although not well received at the time, has become a cornerstone of modern remineralization efforts.

Today, after generations of pulling minerals from soil without replacing them, soils around the world have become depleted and increasingly unable to meet the demands required by the growing population, spurring greater interest around the practice of remineralization.

Rock Dust Soil Amendment Production R&D

As a developing industry, the use of rock dust as a soil amendment is not well established. While progress has been made, there is still a lot of research to be done – many variables remain unknown and the widespread variation in rock dust sources poses a particular need for testing with every project.

Rock dust typically cannot be used readily out of the ground; it will require crushing and sometimes drying to create a suitable rock dust soil amendment powder. However, while a powder promotes faster delivery, it poses significant challenges in terms of dust, complicating transportation, handling, and application.

For this reason, many producers are looking to agglomerate rock dust into larger, dust-free particles that are easier to handle and spread – a practice widely used in the fertilizer and soil amendment industries already. It may seem counterintuitive to crush rock dust only to agglomerate it, but when tumble growth (non-pressure) agglomeration techniques are used, a premium soil amendment product is created. Granules created via tumble growth agglomeration can be tailored to specific crush strengths and other characteristics to help control the release rate of the minerals, among other factors.

“Each source of rock dust is unique – unique in its geology, its physical characteristics, in how it will perform as a soil amendment, and even in how it will respond to agglomeration” states Chris Kozicki, FEECO Process Sales Engineer. “We are seeing a lot of producers looking to develop an agglomeration process optimized around their particular source of rock dust to create a product with the specific characteristics their customers are looking for.”

The Innovation Center has long served as the premier facility for the testing and development of custom soil amendment and fertilizer products and processes, with a wide range of testing capabilities available at batch and pilot scale. This includes drying, compaction granulation, and various methods of tumble growth agglomeration such as pelletizing and conditioning.

Benefits of Remineralization

Soil remineralization is increasingly being recognized as holding the potential to solve an array of issues. Numerous studies around the use of rock dust for improving soil fertility have been carried out with successful results. Some of the many benefits of remineralization are summarized below.

Improved Plant Health

According to a presentation given at a recent conference in Copenhagen, Denmark, remineralization can promote disease and pest resistance, increase nutritional value (and taste) of crops, and even increase yields. When carried out properly, remineralization can also be used to increase soil carbon levels.¹

A Slow-Release Fertilizer

Since minerals are released into soil through the weathering process, the use of rock dust serves as a natural, slow-release fertilizer. This provides long-term results and is especially valuable in areas of high leaching activity, because the minerals are much less soluble compared to a traditional fertilizer product.

Reduced Acidification

Soil remineralization also looks to be a promising means of reducing the global soil acidification problem as well; upon weathering, silicate rocks produce an alkaline leachate, helping to neutralize acidic soil, which is a critical factor in nutrient uptake and other growth factors in plants.²

Enhanced Nutrition

Furthermore, unlike most traditional fertilizer products that focus on the primary macronutrients, rock dust is often host to a wide range of both macro and micronutrients, providing a more well-rounded approach to nutrition. It can also provide silica, which is important in strengthening plant structures and aiding in pest resistance.

In addition to remineralization’s many benefits to soils and plants, there are some other potential benefits to the practice as well:

Reduced Reliance on Chemical Fertilizers

As a natural, readily available material, rock dust can also serve as an alternative to chemical fertilizers. While chemical fertilizers will still play a crucial role in feeding the global population, rock dust could be especially valuable in areas that rely heavily on nutrient imports.

This is perhaps most exemplified by Brazil – a key contributor to global agriculture and food supply; while Brazil only contributes 2% of global fertilizer production, the country is the fourth largest consumer.³

A low-cost, locally available source of nutrients could be a big boost to the industry’s agriculture sector by reducing the need for more costly nutrient imports.

An Outlet for Industry Waste

The use of rock dust could also be a valuable outlet for the aggregate industry’s waste. Rock dust is often a by-product of the aggregate industry (called quarry fines or quarry dust), typically without large-scale beneficial reuse opportunities. This results in stockpiles of unsalable dust, though research around reuse applications has been on the rise.

This quarry dust could be used by the agriculture industry to reduce fertilizer costs and improve soil conditions (depending on the geology).

A similar situation exists in Michigan’s upper peninsula, where “stamp sands” – historic mine tailings – are being sought for use as a fertilizer.

Carbon Capture

Remineralization is also being explored as a method of carbon capture.²  

About Rock Dust for Remineralization

It’s important to recognize that not all rocks have an appropriate geology for use as a tool in soil restoration; some rock types offer greater performance over others.

Igneous, or magmatic rock formations, are especially favorable for remineralization applications. For this reason, the soil around young or active volcanoes is known to be particularly fertile; volcanoes pull minerals from deep underground and deposit them as part of the lava upon eruption. The lava then hardens into igneous rock, ultimately weathering and depositing the nutrients back into the soil over time.

Rock dust may also be generally referred to as any of the following:

Rock dust combined with biochar has also been recently examined with promising results. Biochar is another trending soil amendment touted for its soil restoration capabilities. Together, the two materials could be a highly beneficial tool in soil restoration.


Remineralization, or the application of rock dust as a soil amendment, looks to be an especially promising technique in the effort to restore degraded soils. Its recent surge in interest has shown in many producers exploring the development of new soil amendment products from rock dusts.

The FEECO Innovation Center remains the go-to facility for process and product development around custom soil amendment products; our extensive processing experience with hundreds of materials in both agglomeration and drying allows us to create a process tailored around the goals of the product. For more information, contact us today!

About the Authors . . .

Chris Kozicki is a Process Sales Engineer and agglomeration expert.

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Carrie Carlson is a technical writer and visual designer.

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