An amazing system

Healthy soil provides plants with exactly what they need.

The incredible soil food web, greatly simplified. Each level of soil life feeds on the level below it to produce natural fertiliser.

There’s a complex ecosystem in the soil under our feet. It’s a community teeming with organisms, such as bacteria, fungi, protozoa, nematodes, mites and many other microscopic and larger forms of life. This ecosystem is often referred to as the soil food web. Astonishingly, more than a billion organisms can exist in 1g of healthy soil.

Bacteria and fungi work to decompose (break down) organic material. A second level of organisms, such as nematodes, arthropods (a form of insect) and protozoa (small single-cell life-forms that tend to exist as parasites), feed on the bacteria and fungi. These in turn are fed upon by bigger nematodes and arthropods, and other higher level predators.

As each level feeds on the level below, a waste product is produced which could be thought of as microscopic manure. This natural fertiliser is created on a daily basis. Incredibly, the fertiliser is produced in proportions which exactly suit the dominant type of plant life in the area.

In a forest environment, the soil has a very large ratio of fungi present in comparison to bacteria. In a grassland, there are more bacteria and fewer fungi. In each of these two examples, very different types of nutrients are required, but due to the intricate soil food web, every plant will find just what it needs.

Foundations for Farming (FFF) is a Zimbabwe-based NGO that teaches conservation agriculture practices to farmers, based on Christian principles. FFF provided the information for this article. Visit