Near-saturated Hydraulic Conductivity and Water Retention in Coarse Podzol Profiles

Abstract

There is little information available about the hydraulic conductivity of coarse podzol profiles where the vertical variation of the structure is considerable. The near - saturated conductivity of two coarse podzol profiles was measured by tension infiltrometer. The extrapolated saturated conductivity was 106.9 cm h- 1 in the very coarse sand and 16.7 cm h- 1 in the medium coarse sand parent soil, and decreased steadily upward, being between 0.7 and 1.3 cm h-1 in the two top horizons of these profiles. The unsaturated conductivities measured by the instantaneous profile method were in good accordance with the results of the tension infiltrometer, but the measurement range of the instantaneous profile method was rather narrow. The near - saturated hydraulic conductivity and water retention changed in both profiles in a systematic way, which agrees with the differences in matrix scale of structure as reflected in the measured soil textural and pedogenic properties.