Measuring Saturated Hydraulic Conductivity using a Generalized Solution for Single‐Ring Infiltrometers

Abstract

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 (Ks) were developed and tested in this study. The Ks 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 Ks values calculated from the simulated infiltration curves of representative soil textural types were in the range of 87 to 130% of the real Ks values. Field infiltration tests were conducted on an Arlington fine sandy loam (coarse‐loamy, mixed, thermic, Haplic Durixeralfs). The geometric means of the Ks values calculated from the field‐measured infiltration curves by Method 1 and Method 2 were not significantly different. The geometric mean of the Ks calculated from the detached core samples, however, was about twice that of the Ks calculated from the infiltration curves, which was consistent with earlier findings. Unlike the earlier approaches, Method 1 calculates Ks values from the whole infiltration curve without assuming a fixed relationship between saturated hydraulic conductivity and matric flux potential ϕm