Written by Peter Kolb, Montana State University
Soil water availability is the capacity of a soil to hold water that is available for plant use. A soil is simply a porous medium consisting of minerals, organic matter, water, and gases. The traditional definition of soil is: Soil is a dynamic natural body having properties derived from the combined effects of climate and biotic activities, as modified by topography, acting on parent materials over time.
Figure 1. Diagram