The permanent wilting point is the soil moisture level where plants are no longer able to draw water from the soil. The available water capacity is the amount of water between the field capacity and the wilting point. By calculating the percentage that each of these particles contributes to the soil sample, you can calculate what type of soil you have. Loam, in the center, is considered the ideal soil for growing plants. Sand is the coarsest type of the three, typically having a size of 1 - 2 mm, the graininess is easily felt when rubbing it between your fingers.
Silt is a much finer textured soil type than sand.
It is generally approximately .5 - 1 mm in length and only a small amount of grit can be felt when rubbing it between your fingers. Clay is the finest in particle size of the soils. Its size is approximately .05 - .5 mm in length. When rubbing this between your fingers, you should not feel any grittiness at all. Introduction Methods Glossary References Data Sheets Questions Menu Objectives Understand what materials soil are composed of.