FIELD MEASUREMENT AND USE OF SOIL-WATER PROPERTIES

The hydraulic conductivity versus soil‐water content relation for different soil depths was measured in the field for three soil profiles. The soils varied in physical properties from homogeneous to heterogeneous with depth and from loamy sand to silty clay in surface soil texture. Hydraulic conductivity values calculated from drainage data taken during different time intervals compared favorably with each other and showed no measurable hysteresis. The soil‐water flux at various soil depths with and without evaporation at the soil surface was measured. The rate at which water drained from each of the profiles was predicted using Darcy's equation and some simplifying assumptions. The agreement between theoretical and measured results is discussed in terms of soil heterogeneity with depth. Copyright 1969 by the American Geophysical Union.