…and the plants will take care of themselves.

It's easy to understand, when you dig your hands into rich, well-aerated soil, that soil itself is a living thing. There are the worms and bugs, of course, of an astonishing - and sometimes icky - variety and density. And there are many millions more creatures in any handful of healthy soil that are too small to see. There's the spongy, elastic feel of a handful of soil that resembles yeasty bread dough. There's the rich, complex scent - the only word is "earthy" - that we all know.

Bored? Ok, ok, fine, skip down to "How is Soil Relevant to the Transition Initiative?".

What is Soil?

It's not dirt. Dirt is what you dig out from under your fingernails after a day of working with soil.

Soil starts with mineral components: sand, clay and silt. (To go even further back, sand, clay and silt are created by various mechanisms such as erosion and the chemical action of lichens and fungis on stone.) Organic matter (for example leaves falling from trees) blends with the mineral components and is devoured by various soil inhabitants, such as bacteria, fungi, nematodes, protozoa, worms, etc. After decomposition, leftover organic matter that is too fibrous to be digested ("humus") mixes with the mineral components to provide a loose, nutritious aerated blend that holds moisture. (Plant roots generally prefer a ratio of about 25% water and 25% air to 50% soil.)

Hungry Soil

Soil is highly active - the more active the better. As organic matter is added to soil, creatures in the soil devour and process it, living out their own life cycles and contributing organic matter via their excrement and their own consumption and decomposition. At the same time, a web of predators and prey exists among the soil creatures themselves. There are complex activities and relationships that are not well understood, such as the symbiotic relationship between mycorrhizae fungus and plant roots, where the fungus and the root mesh, each providing the other with beneficial nutrients. Another example is the dramatic changes that occur from one insect life-cycle to the next, during which a single insect can metamorphose from benign prey to voracious predator, from neutral or even beneficial garden resident to damaging pest.

Killing the Soil

Non-organic agricultural methods use inorganic fertilizers to artificially raise the fertility level of the soil. This results in weaker plants that are more vulnerable to pests and disease, as inorganic fertilizers focus on a subset of soil nutrients (mainly the N-P-K combo) that focus on specific aspects of plant growth rather than providing the spectrum of nutrients available in organically maintained soil. Inorganic fertilizers also damage the soil by leaving residual toxins, which both reduce soil fertility and leach out into the water table affecting the surrounding environment.

Inorganic fertilizers ignore the complexity of soil biology. There's much more going on in soil than the amount of nitrogen (N), phosphorus ( P) and potassium (K) it contains. There are many nutrients required for balanced soil fertility, and many methods by which those nutrients are created, processed and distributed among soil inhabitants. 

Artificially raising the levels of specific nutrients disrupts the organisms that, in well-treated soil, provide a balanced growing medium. Once the soil is sufficiently damaged, it requires continued application of inorganic fertilizers because it no longer has the biological strength and diversity to create soil nutrients from organic activity.

In a soil ecosystem imbalanced by inorganic fertilizers, plants are more vulnerable to pests and diseases and the soil itself supports these infestations by being less ecologically diverse. Less diverse ecologies are more vulnerable than diverse ecologies because when a single predator or disease finds a successful niche it has less competition and opposition to slow its spread. This leads to the use of pesticides and herbicides and engineered (up to and including GMO) plant varieties, which further damage the soil and the surrounding ecosystem.

Feeding the Soil

Organic gardeners and farmers feed the soil rather than feed the plant. Rather than reducing the biological complexity and activity of the soil, organic agricultural methods support it. Organic matter is added to the soil with the expectation that the complex web of life in the soil will use it to further its own ends and, as a byproduct, create an environment where plants thrive. Plants only need to be artificially fertilized when the soil can't do its natural job.

How is Soil Relevant to the Transition Initiative?

Transition Initiatives build mechanisms for communities to cope with the increasing price and scarcity of non-renewable energy sources. Our industrialized agricultural system is highly dependent on petroleum, natural gas, phosphorus and other non-renewable components:

• Fertilizer sources: Inorganic fertilizers are mostly made from non-renewable sources. For example phosphorus, the "K" in the "N-P-K" equation, is extracted from phosphate rock that is mined in various places around the world, including China, Morocco and the US. Because it is a diminishing resource there are increasing geopolitical issues regarding its access. China imposes a 135% tariff on exports; the USA no longer exports phosphor rock and has signed a bilateral trade deal with Morocco that guarantees access to mineral resources (some of which are located in the contested Western Sahara). Sound familiar? It should. Some people think that peak phosphorus might be reached as early as 2033.
• Fertilizer processing: Energy is required to convert inputs into usable fertilizers. According to the United Nation's Food and Agriculture Organization (FAO), the nitrogen component of inorganic fertilizer requires 1.5 tons of oil equivalents to make 1 ton of fertilizer. The price of inorganic fertilizer rises as the price of oil and natural gas (other components and sources of processing energy) rise.
• Transportation: Fertilizer distribution, both of the sources and of the finished product, is a global operation that requires non-renewable resources for transportation.

Non-organic agricultural systems face the same imminent challenges as all other activities that are based on non-renewable resources. Scarcity - both of non-renewable resources and agricultural land made toxic by non-organic farming methods - will cause price increases and food shortages. The only question is when.

There is nothing more fundamental to community resilience than reliable, local and affordable food.

Sources and More Information

• Hermary, Heide, "Soils I", "Soils II". Handout. Residential Landscape Technician diploma program. (Instructor Amanda Jarrett) Douglas College. Sept. 2009. Print (The Gaia College website organizes  Organic Master Gardener courses that use this course material.)
• Nardi, James B. Life in the Soil Chicago: The University of Chicago Press, 2007.
• The Soil Association website, including the policy papers "Just say N₂O: From manufactured fertiliser to biologically-fixed nitrogen" and "A rock and a hard place: Peak phosphorus and the threat to our foo..."
• Soil, from Wikipedia
• Fertilizer, from Wikipedia
• Soil life, from Wikipedia