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) has a moderate soil density for a clay loam at 1.26 g/cm³ which indicates an slight compaction. The drainable porosity in the A1 horizon is at the ideal value of 10 % which indicates the topsoil has large number of macropores resulting in good aeration to support root functions. However, the surface saturated hydraulic conductivity at only 32 mm/hr is very low which suggests these macropores are not well connected or functional resulting in lower than expected infiltration and drainage rates, which is surprising given the undisturbed nature of the tree row. The A1 and AB horizons contain 16 % to 22 % plant available soil moisture, of which 6.9 to 8.4 % is readily available for tree growth. Given the depth of these horizons that translates to a PAWC of 66.7 mm and readily available soil moisture of 26.5 mm to a depth of 34 cm. The two medium heavy clay B horizons retain around 5% drainable porosity which is good for a clay subsoil and around 5% readily available soil moisture, however around 32% or a total of 187 mm soil moisture is not available for plant use.