Measuring saturated hydraulic conductivity using a generalized solution for single-ring infiltrometers

Saturated hydraulic conductivity is a measure of the ability of a soil to transmit water and is one of the most important soil parameters. New single-ring infiltrometer methods that use a generalized solution to measure the field saturated hydraulic conductivity (K s ) were developed and tested in this study. The K s values can be calculated either from the whole cumulative infiltration curve (Method 1) or from the steady-state part of the cumulative infiltration curve by using a correction factor (Method 2). Numerical evaluation showed that the K s values calculated from the simulated infiltration curves of representative soil textural types were in the range of 87 to 130% of the real K, values. Field infiltration tests were conducted on an Arlington fine sandy loam (coarse-loamy, mixed, thermic, Haplic Durixeralfs). The geometric means of the K s values calculated from the field-measured infiltration curves by Method I and Method 2 were not significantly different. The geometric mean of the K s calculated from the detached core samples, however, was about twice that of the K s calculated from the infiltration curves, which was consistent with earlier findings. Unlike the earlier approaches, Method 1 calculates K s values from the whole infiltration curve without assuming a fixed relationship (α K s /Φ m ) between saturated hydraulic conductivity and matric flux potential Φ m .