soil wets up during rain organic matter soil wets up during rain air soil dries down mineral matter water solids pores Figure 5.1. Distribution of solids and pores in soil.

Figure 5.3.

a) sand b) dense clay c) aggregated loam wilting point field capacity plant-available water a) sand unavailable water gravitational water b) dense clay plant-available water unavailable water gravitational water c) aggregated loam unavailable water plant-available water soil water content saturation Figure 5.4 Water storage for three soils. (Shaded area represents water stored in soil that is available for plant use.)