Soil Building Basics 2: Protect Soil From Disturbance

"Whatever takes place each day in this world beneath our feet has wide-ranging influences on some of the greatest issues off our time - pollution, nutrition, and health, global warming and preservation of biodiversity."

-James B. Nardi,

author Life in the Soil

I originally came to love soil from a background in geology. I knew soil mostly from the mineral and physical structure of it. According to what I was taught, it could take hundreds of centuries to build a mere inch of topsoil from bedrock. At the rate we were eroding soil (erosion rates in Kansas are apparently equal to that of the steep-sloped Himalayas!), it was terrifying.

But then something remarkable happened.

I learned about the soil food web.

It turn out, soil biology changes EVERYTHING!!

A geologist named David Montgomery and his partner and biologist, Anne Biklè, are a couple in Washington state who became enthusiastic about the teeming world underground. They relate a story of how they bought a piece of property with a subsoil that was originally hard as concrete and how they grew soil surprisingly fast to became a thriving garden just a few years later:

"In graduate school, Anne and I were also taught that it takes centuries to build an inch of topsoil. That’s a reasonable estimate of how long it takes nature to make it. But we were finding in our yard was that Anne had made a couple of inches of new topsoil in half a decade. So that made us think, “How is it possible for that to happen so fast?” (1)

They went on to write The Hidden Half of Nature: The Microbial Roots of Life and Health where they talk about their evolving perspective of the role of biology in the soil and in humans also.

Tapping into the the importance of biology in the soil changed my entire understanding of soil, how it was built and how it thrived.

Protect from Biological Stressors : overgrazing (if that applies to you) or trampling or anything that diminishes plant leaf cover will limit it's ability to take in sunlight to make sugars to then go on to feed the soil... Now some disturbance like pruning or grazing can be super helpful to cycle nutrients and even stimulate better plant growth! Just not too much. The Goldilocks principle, essentially: not too much of this or that, but rather they like it just right! Avoid practices that become significant stressors for your soil or landscape.

Protect from Chemical Stressors : pesticides, herbicides and, believe it or not, synthetic fertilizers (think bright colored, granular nitrogen and phosphorus fertilizers that dissolve easily in water) can actively break down soil structure, drive away microbial life and sever relationships between the microbes and plant roots. They essentially compromise the plants' "immune system." AND, in the case of synthetic fertilizers like phosphorus and nitrogen, they can burn through the carbon-rich organic matter that is like a sponge in the soil.

What?! Not the SOIL CARBON SPONGE, you say!

Yes. They destroy the sponge.

Whoa. Not THAT! Anything but that?!

I know.

Synthetic fertilizers are used because they do work in boosting yields but it is often at the expense of burning through organic matter in the soil. That can mean soil degradation. Erosion. Desertification. Yet we are learning we can use soil biology to maintain and even boost yields while also building soil! It was new to me, and apparently to modern conventional agriculture, but not a new concept. There are examples around the world of people who have farmed the same piece of land for THOUSANDS of years while also building soil! Soil Health is the next paradigm shift in how we do gardening and agriculture! It's proven science and the idea is catching as more farmers realize the economics work in their favor. Less input costs, better yields, better resilience in the face of drought or flooding. Switching to organic fertilizers - ones that feed the soil, contain trace elements, and support the microbes - is one simple move that backyard gardeners, land and lawn managers can use to make such a difference over time for their own soil health.

And a note about pesticides: there are effective, low-impact options out there for you, if you need them. I often look for OMRI-certified or organic labels if pesticides are needed, but in general, use them sparingly to support health of your system, not as a crutch. Fungicides, for example, sprayed on the soil don't just get the "bad" fungi, they affect all the fungi in the soil. And as our understanding of some so-called parasitic fungi improves, we find that some are actually hugely important for boosting the immune response of plants. Some of them are actually plant "shields" and when we kill them off, we actually compromise the health of our plants we thought we were protecting! Same with insect "pests": many readily-available, chemical pesticides kill insects indiscriminately. They often kill both the "pest" and their beneficial insect predators, only the predators can't recover as quickly as the pests from a spray. So we unintentionally create our worst case scenario: ideal conditions for our pest populations to explode, no predators to stop them, and perfect opportunities for pests to become resistant to whatever it is we are applying. This makes us spray harder and more regularly just to keep them in check. Not a fun cycle for anyone.

These are many simple ways to protect your soil and minimize disturbance. Every time you put a shovel in the earth, do it mindfully and only as needed. The soil beneath our feet is alive. Listen to, learn from, and work alongside this thriving community thrumming beneath our feet.

(1) Interview with David Montgomery: https://www.cornucopia.org/2017/12/mulch-soil-inside/

(2) Article in the Guardian about biologist Anne Biklè and geologist David Montgomery: "The scientists whose garden unlocked the secret to good health" https://www.theguardian.com/science/2015/nov/29/anne-bikle-david-montgomery-hidden-half-nature-microbes