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 s 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 1 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