Composition and Types of Soil: What is soil? It is a complex mixture of minerals and organic matter. The minerals come from the disintegrated rock, the organic matter from decomposed plant and animal matter. Mixed in with this is water, air and numerous living organisms. The main function of soil is to provide plants with nutrients, water, oxygen and anchorage for the root system. Soil is constantly changing. Natural changes include the weather, insects, worms, bacteria and fungi. Adding fertilizer, chemicals and mulch can completely alter soil type. Most soil falls into two categories: heavy or light depending on the amount of clay or silt (fine particles) or sand (coarse particles) they have. Clay is made from very fine particles that pack together closely, thus hindering the downflow of water and air which are both essential for plant growth. Gypsum can break this up and allow the plant to take in water and air.

In clay soils in a large downpour, plant root may end up very wet and stay wet resulting in the rotting of tree roots - the spaces between clay particles are filled with water. Sandy soils are light because they are much easier to dig when wet or dry. Sandy soil drains faster but they may dry out too fast.Sany soils must be have rainfall more frequency. They must also be fertilized more often since their nutrients wash away quickly. Loamy soil is half way between the two and is ideal for plants. To identify soil types, follow the steps below ...