PDC Day 7: Soil is Alive; Dirt is Dead

“The Nation that destroys its soil destroys itself.” (Franklin Delano Roosevelt)

Soil is alive. Dirt is dead.

It’s a viscous spiral that starts with tilling and ends with dead dirt, eroded land and polluted waterways.

Annapolis Valley field, Medford

A teaspoon of healthy soil contains billions of bacteria, fungi, protozoa and nematodes.

Tilling kills micro-organisms in the soil, resulting in a temporary rush of available nutrients from their dead bodies.

After a few years of tilling, the loss of soil fertility becomes obvious.

So we add fertilizers, which kill off healthy bacteria that support and protect plants.

The plants weaken without these allies, and become more vulnerable to pests.

So we use pesticides, which destabilize the life around the plant, opening up space for weeds.

Heavy clay soil in the wet east end of the property

So then of course we use herbicides to kill the weeds, but now the soil is dried out and lifeless so it doesn’t hold water and we have to irrigate.

So now we’re depleting the water table just when we’ve become more vulnerable to drought.

But wait, there’s hope. Fields can be rejuvenated. And within a few years, they can be restored to fertility, so powerful are the natural processes that have developed over millions of years, much longer than Homo sapiens has been kicking around.

Keyline ploughing is a technique of decompacting soil without turning it over. It allows the ground to absorb water that would otherwise run off. A diverse grass mixture is planted to restore life to the soil. In a few years the field will be ready for a swale system designed to retain rainwater, and a polyculture food forest.

A compost tea can be applied to restore bacterial life to the soil. This tea is made with high-quality compost and actively aerated as it is brewed. It can be sprayed over a wide area.

There are methods of making compost that is teaming with life to inoculate the soil with microorganisms.

A well balanced soil will naturally resist the forces of acidification so that lime need not be applied.

Similar techniques can be applied on the home scale. Mulch is the answer to many questions. Mulching increases reproduction of soil microorganisms, which increases their poop as well as their die-off, all of which adds fertility to the soil.

Loamy soil just inside the woods

We collected soil samples from several spots on the property and found sand, silt and clay in different places.

The soil on the east end of the property, which is perpetually wet underfoot, is clay, as Graham suspected. It will lend itself to different treatment and features in our permaculture designs for the property.

Stay tuned for that!

 

 

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