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.

Overall the topsoil seems to be well structured. The A11 and A12 topsoil horizons have low bulk density at 1.06 g/cm³ and 1.17 g/cm³ respectively. Other indicators of good structure include the drainable porosity at 17.8 % and 10.5 % which indicate the topsoil is ideal for root growth and function, and the high saturated hydraulic conductivity of the A11 horizon at 150 mm/hr which indicates the presence of well connected macropores. The A2 horizon is however extremely compact having a bulk density of 1.73 g/cm³, and a drainable porosity of only 5.5 % which is below the ideal level of 10 % required for good root growth and function. This compaction in the A2 is a natural feature of these soils. Despite differences in compaction the water retention properties of the three A horizons are quite similar, plant available soil moisture ranges from 18.5 to 30.2 % whilst the readily available soil moisture ranges from 7.1 % in the A2 horizon to 12.2 % in the A12 horizon. Combined the three A horizons hold 118 mm plant available soil moisture and 47.4 mm readily available soil moisture. Whilst the two B horizons are not overly compact, they hold minimal plant available water at 10.1 to 13.4 % and minimal readily available soil moisture at 3.6% to 5.0 % as the majority of soil water held in the two B2 horizons at 28.3 % to 45.9 % is not available for plant use.