Soil Hydrology Overview

This data reflects both the quality of the soil structure, the amount of water available for growth and the ease by which these soils are able to be irrigated. The data indicates how much water is available for vigorous tree and fruit growth, as well as how much water is available for tree maintenance and survival. This data can also be used to better schedule irrigation, and compare irrigation requirements between soils.

The topsoil (A1 horizon) appears to be slightly compact having a bulk density of 1.33 g/cm³, yet in other respects is well structured as it has a high saturated hydraulic conductivity at 220 mm/hr. The drainable porosity is 14.2 % which exceeds the desired level of 10 % required for good root function. Despite having good soil structure the A1 horizon holds a relatively small amount of plant available soil moisture at 10.7 % or 10.7 mm, of which only 5.0 % or 5.0 mm is readily available to support rapid growth (Green Figure 3), an additional 5.7 mm soil moisture is available to the tree but at a cost to growth (Orange Figure 3), whilst 25.4 mm is not able for use by trees (Red figure 2). The B1 horizon has considerably less drainable porosity at 6.1 % which is not unexpected for a subsoil, yet has similar readily available soil moisture at 4.4 % and 8.9 mm to that of the A1 horizon. The majority of moisture in the B21 and B22 horizons at 35.2 % and 33.1 % is not available for tree use.