© WWF / Kevin Schafer

Soil Types

Farming in the rich volcanic soil in the Andes Mountains. Near Cayambe, Pichincha, Ecuador.
Soil is a lot more than just dirt. Soil is what the vegetation depends on for subsistence. It decides what kind plant can grow where. It also provides a home to many types of organisms, from microscopic ones to insects, burrowing animals and others that live above ground. Thinkquest.org has an interesting section that gives you 'the dirt' on soil. It also contains some interesting soil experiments.
Different soil types
There is no one classification of soil types. People describe it in all kinds of ways - sandy, clay or loam; good or poor; heavy or light; and also by how much sand, silt and clay are present it in. Here is where you can find a listing of soil types according to one such classification with their characteristics.

The University of Illinois' extension web site tells about the formation and composition of soil, types of soil, soil profiles and conservation of soil. It also has some interesting soil-related experiments.

Analyzing soil
BBC's gardening site is an useful resource should you want to analyse the soil in your yard, and the Chemistry.org portal has an interesting experiment you can download as a PDF to test the pH of soil to discover how acidic it might be.

Soil conservation
Not surprisingly, the ground beneath our feet is a key focus of conservationists. Soil conservation is a subject of much scientific enquiry.It is essential to know what are the different ways in which we can conserve soil and prevent erosion. For details visit this website.
Read more here about how scientists have developed an innovative new test for a quick and reliable diagnosis of potential contamination sites.