Calculation of Hydraulic Conductivities of Soils from Texture and Organic matter Content

It is demonstrated how the values of the three constants in a convenient formula for the calculation capillary conductivities can be evaluated from texture and organic matter content of a soil. In this way it is possible to calculate the conductivity function of any soil provided that an adequate analysis of granular composition and humus content analysis is available. Particularly for practical purposes the quick availability of the results of this calculation is of great advantage over time consuming direct measurement or calculation with constants evaluated from moisture retention curves. To increase the practical significance of the method the effect of pore size hysteresis on the calculated conductivity functions is accounted for in a pragmatical way. Conductivity functions for a number of single‐layered soil types in the Netherlands are given. In a subsequent paper it will be shown how the discussed method is put into practice in a computation of capillary rise from the groundwater table in multi‐layered soil profiles.