Physical Properties of soil- Introduction

Soil is constituted of three phases, namely the solid phase, air phase and the water phase. The content of these three and its compactness, affect the physical properties of the soil. The content of these three phases can be diagrammatically represented with the help of three phase diagram and two phase diagrams.
A three phase diagram is a rectangular diagram, divided into three parts, according to the respective volume of the three phases of soil.
Generally the volumes are written on the left side of the diagram and the respective weights are written on the right side of the diagram. Three phase diagram is converted into a two phase diagram when one of the phase either the water or the air is absent from the soil.