Rock Dust: The Secret Ingredient to “Cooking Up” a Batch of Healthy Soil


The weather is cold and blustery, which means that soup season is officially here. Nothing beats a bowl of hot soup to feed the stomach and nourish the soul—except perhaps a loaf of hearty, home-baked bread.

Sure, bread gets a lot of bad press these days (too many carbohydrates! too much sugar!) … but there is a world of difference between the processed and packaged stuff that you buy in the supermarket and a loaf of bread made with whole grains and shaped by hand.

Well-made bread doesn’t just taste different, it looks different, too. In fact, it looks a lot like healthy soil as chef Dan Barber observes in his best-selling book The Third Plate: Field Notes on the Future of Food.

“Healthy soil is like the inside of a well-made loaf of bread…moist, textured and filled with irregular bubbles. Unhealthy soil is like cake mix—dry and packed down, with no spaces for air to circulate or organisms to maneuver.”

Irregular pockets of air are what give artisanal bread its yummy, airy chewiness. In healthy soil, these pockets of air give beneficial microorganisms the room they need to move around. Unhealthy soil, on the other hand, is lifeless. Compact and dry, it is a hostile growing environment that limits microbes’ ability to flourish.

The Role of Rock Dust

Naturally healthy soil contains billions of living microorganisms—from bacteria to nematodes, fungi, protozoa, anthropods and earthworms. Each organism has a specific role to play, from the recycling of nutrients to the decomposition of organic materials and improvement of soil structure.

These beneficial microbes depend on rock minerals in the soil to live and to multiply.  Unfortunately, most of the world’s soils are woefully deficient in essential minerals thanks to over farming and other modern agricultural practices.  No amount of organic matter will make up for deficiencies in rock minerals, either. The ultimate result is poor and infertile soil.

Adding fresh sources of rock minerals to the soil enhances the ability of microbes to flourish. It provides micro nutrients and trace elements that are important to the life cycle of plants and mimics the earth’s own natural way of restoring soil health.

The Superior Benefits of Basalt

Crushed volcanic basalt in particular is a superior source of essential plant nutrients, including calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn). The silicon that is derived from basalt helps improve plant structure and stress tolerance, and additional benefits include increased growth and vitality, more colorful plants, more nutritious crops, and vigorous and stronger plants.

So go ahead, enjoy the chilly days of winter with some comforting soup and loaves of delicious, nutritious bread. At the same time, make a mental note to stock up on rock dust. It’s the “missing ingredient” to healthy soil.