Rock Dust: Improving Soil Porosity & Water Conservation

As in many other parts of the country, the Pacific Northwest is experiencing a summer of intense heat and little precipitation—and it’s only mid-season. Flower gardens and vegetable plots everywhere are wilting under the sun, as are the people who tend them.

Understandably, plenty of backyard gardeners are dismayed at the prospect of having to sacrifice the juicy red tomatoes, plump peppers and cucumbers that symbolize summer. It’s either that or pay up…in the form of a hefty water bill.

What’s more concerning, however, are the extreme drought conditions occurring in places such as California and Eastern Washington. There, farmers are scrambling to adapt—or are being forced to shut down operations entirely.

While scientists and politicians debate the reasons behind this massive climate change, one thing is painfully clear: Water conservation and water management should be at the top of everyone’s agenda, before it becomes too late.

Soil Management is Key

When it comes to water retention, the importance of good soil management cannot be overstated. Rich, healthy and well-managed soil is filled with irregular pockets of air, much like the inside of a loaf of home-baked bread. These pockets of air give beneficial microorganisms the room they need to move around. They also help soil retain water, holding onto it like a sponge for plants to use later.

Unhealthy soil, on the other hand, is lifeless. Compact and dry, there is no space for air to circulate or for beneficial microorganisms to move around. It is a hostile growing environment that limits microbes’ ability to flourish. What’s more, compacted soil doesn’t absorb water—it repels it. Water that may already be scarce just runs off, taking along with it any pesticides and synthetic fertilizers that have been used in a last-ditch attempt to bring the “dead soil” back to life. Inevitably, those same chemicals end up in our lakes, rivers and streams.

The Role of Rock Dust

One of the best defenses that plants have in drought-like conditions is the ability to grow deep roots, i.e., roots that can penetrate deep into the soil to access water and other nutrients. They can’t do that in hardened soil. They need rich, porous soil—the kind of soil that crumbles easily in your hand. This type of soil is the result of hard work by billions of beneficial microbes. Bacteria, fungi and earthworms—they all work together to improve the structure of the soil and to create an environment in which thirsty plant roots are able to stretch.

In turn, these hard-working (and hungry) beneficial microbes need sustenance. To live and multiply, they depend on a steady supply of rock minerals. The problem is that most of the world’s soils are woefully deficient in rock minerals. Absent a volcanic eruption or the world’s fastest moving glacier, getting rock minerals back into the soil will require human planning and intervention.

One way to ensure that there are enough minerals in the soil is to apply a layer of finely milled rock dust. Plants don’t have to work nearly as hard to survive in soil that is properly mineralized. And while almost any type of rock dust will improve the soil, all-natural volcanic basalt is the best for delivering a wide array of essential minerals, including calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn). Basalt also contains soluble silicon which contributes to the strength of cell walls and makes crops more resistant to pests and disease.

Waste Not Want Not

Water is the key to our existence. But it is also improves the quality of our everyday lives in hundreds of different ways, from the flowers we grow to beautify our homes and neighborhoods to the nutrient dense food we produce to nourish our bodies and feed our souls.

The good news is that people are waking up to the fact that how we treat our soils affects our ability to manage the precious water that we already have. Hopefully, this awareness won’t wash away with the next rainfall! Let’s treat water—and the soil that filters and retains it—as the precious resources that they are.