THE SOIL is the basic raw material

The soil is the basic raw material of the  gardener’s art. It should never be dismissed as a mere collection of mineral particles he soil is the basic raw material of the used to anchor roots, or worse still as “dirt.” It is much more than that. Certainly, its basic structure consists of rock particles broken down by frost and thaw action, wind and river flow, to produce the different textures that give us soil “types”.

However, a large part of its makeup is organic matter—vegetable and animal remains in various stages of decay—along with air and water, which are all essential for the support of plant and animal life. All of this provides a home for millions and millions of living organisms such as soil fungi, algae, bacteria, insects, and worms, which work to provide just the right conditions for healthy plant growth. These organisms provide the plants with food in a form they can ingest and improve the structure of the soil by breaking it up and allowing more air to circulate. It is perhaps in the treatment of soil, more than anywhere, that organic gardening differs from other gardening methods. The very first principle of organic gardening is to nurture and encourage this subterranean life so that it can support a much larger plant population than nature ever intended

THE FORMATION OF SOIL

Soil is formed over millions of years by the physical or chemical weathering of rock. Clay soils are formed by chemical weathering, where the mineral composition of the rock is changed usually by the action of weak acids. Other types of soil are the result of physical weathering, which does not involve any change in the chemical content of the rock, but gradually erodes it mechanically. This physical weathering may happen within the rock or externally.

In hot climates, such as those which prevail in desert areas, the widely fluctuating temperatures of day and night cause rocks to expand and contract regularly. Over a period of time the stress caused by the continual expansion and contraction leads to the physical disintegration of the rock and the formation of soil particles.

In colder conditions, like those that affected much of the world during the last Ice Age, rocks are broken down by the action of water entering cracks in the rock and freezing. As it freezes, the water expands, forcing the rock to split open. The movement of giant glaciers was responsible for the formation of soil as it wore away fragments of the rock below, and the action of streams and rivers also serves to wear away rocks to form soil.