ABSTRACT
The purpose of this chapter is to introduce basic concepts related to the amount and energy state of water in soil. These concepts are prerequisite to quantify and manage soil water storage, to obtain predictions concerning rates and directions of water flow and solute transport, to utilize soils as building or foundation materials, and for many other purposes. The term soil water is used here to represent the soil liquid phase which is typically a water solution containing dissolved salts, organic substances and gases.
