The Soil Food Web

Instead of trying to feed our plants directly, we should trust that they can fend for themselves and start feeding our soil. If nutrients are available in a healthy ecosystem, your plants will find them. As gardeners, it is important to understand our relationship and role within The Soil Food Web.

The Cycle

  1. Plants make sugars through photosynthesis, which are then pushed into the soil through their roots.

  2. Bacteria and fungi cluster around plant roots to eat these sugars.

  3. Protozoa like amoeba then eat these bacteria and fungi.

  4. The waste products from these protozoa are deposited right next to the plant roots (in effect, directly feeding the plant).

  5. Everything living will break down into the soil, releasing nutrients. Insects are the first decomposers to come along. Rolypolies, millipedes, beetles and other insects shred things like fallen leaves and dead animals into smaller parts, making them edible for bacteria and fungi.

  6. Earthworms and protozoa eat bacteria and fungi and their waste products feed plants.

So what happens in our gardens? Why does this cycle often seem to fall apart?

In nature, plants don’t need fertilizers. They are able to control what nutrients they get by controlling the sugars they released. The truth is that inorganic fertilizers dehydrate the soil, kill microorganisms and make plants dependent on this high concentration of nutrients, most of which leech out of the soil. Of course, inorganic fertilizers have their place. They work well for temporary annual baskets and planters, which don't need to be sustainable for an extended period of time. Microorganisms hold nutrients in place, keeping them from washing away or being eroded by the wind. Once this failsafe is removed, fertilizers (which do not include all of the micronutrients plants require) must constantly be applied.

Heavy fertilizing creates plant growth, that’s what it’s for, but because it doesn’t contain micronutrients, the plant cannot properly regulate the amount of nutrients they need.

This causes fleshy, watery growth that stresses the plants out and draws insect pests. Insects love this watery growth, which further weakens the plant, leaving them vulnerable to more attacks. The use of pesticides is not specific to these pests and will also kill predatory species which might ordinarily control pests, now letting them run rampant all over your plants. Plants can also suffer from bad bacteria and fungus.

Good bacteria and fungus make long term associations with plant roots. Once established, they outcompete bad bacteria and fungi. Blasts of inorganic fertilizers kill these protective networks, leaving plants vulnerable to fast growing, harmful species. These bacteria and fungi are opportunists and can only attack plants without beneficial associations. In nature, this gives plants who make these associations with beneficial bacteria and fungi a huge advantage.

Steps towards establishing a healthy ecosystem:

Step 1: Identifying what kinds of plants you have and their needs.

Fast growing, herbaceous plants like annuals and perennials have different needs than slower growers like trees and shrubs. In nature, herbaceous plants will occupy an empty landscape first. These plants germinate easily, have short growing seasons, and are able to reproduce with a small investment of nutrients.

The more permanent a plant is, the more it can benefit from a fungal association, and impermanent plants that grow quickly, but die when the growing season is over, can be better supported by bacteria. These colonies are similar in that they break down dead matter and reproduce quickly. Bacteria and herbaceous plants go hand in hand, impermanent, but essential for establishing a good permanent ecosystem. Trees and shrubs make permanent associations with fungi. This allows for slow and steady food and water year round.

Step 2: The World of Soil