1.2 CRITTERS AND MICROBES
We believe healthy soil results in healthy plants. Healthy plants result in healthy food. Healthy food results in healthy people. So we need to look after the soil. By "healthy soil", we mean soil with astronomical numbers of living things, in huge diversity - tens of thousands of species of microorganisms (not to mention earthworms, insects, spiders, etc.).
The best way to establish and maintain soil health is with the addition of organic matter - mainly composts and mulch. And to never use artificial chemical fertilizers and pesticides, as these will eliminate many beneficial species causing an imbalance in the soil biology. Soil borne pests and diseases attacking plant roots are often simply a result of an imbalance in soil biology (just as pest and diseases attacking the above-ground parts of the plant are often simply the result of an imbalance).
In healthy soil, nematodes that have the potential to attack plant roots, are kept in check through attack by beneficial nematodes. Other species of beneficial nematodes have the ability to control pest species such as weevils while they are still in their larval stage in the soil. A massive outbreak of pests or disease is a symptom of an imbalanced system.
Earthworms are good indicators of soil health, and they are easy to see - so do what you can to increase earthworm numbers, and soil health will also improve.
Soil fungi effectively increase the root volume of trees, thereby improving access to soil nutrients and tree health. Soil fungi are sensitive to cultivation and the application of artificial chemical fertilizers/pesticides, so these practices should be avoided for optimal soil/plant/human health.
Tree and Understorey Life
The greater the diversity of species living in and under the trees, the smaller the risk of a severe outbreak of pests or disease. We get a lot of help from spiders, tree frogs and wasps - these are the things that eat the things that eat our trees or fruit.