About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in SSSAJ

  1. Vol. 27 No. 2, p. 123-126
     
    Received: May 7, 1962
    Accepted: Sept 28, 1962


 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2136/sssaj1963.03615995002700020011x

Porosity and Soil-Water Diffusivity Relations1

  1. Ray D. Jackson2

Abstract

Abstract

Water at −2mb pressure was absorbed by horizontal columns of three soil materials of differing texture each at three porosities, each porosity in duplicate. The soil materials were Adelanto loam, Pachappa loam, and Pine silty clay. From the water content distributions, soil-water diffusivities were calculated, assuming applicability of diffusion theory. For a total porosity change of about 0.05, Pachappa loam exhibited little change in soil-water diffusivity but Adelanto loam and Pine silty clay exhibited twofold to threefold changes in diffusivity at the same relative water content. Cumulative infiltration and distance of penetration of water into horizontal soil columns decreased 50% and 40%, respectively, for Adelanto and Pine and 15% and 12%, respectively, for Pachappa when the total porosity was decreased 0.05.

Water content distributions were calculated using exponential diffusivity-water content functions obtained by a least squares fit to the diffusivity data measured over a limited water content region. Predictions of water contents based on these functions were considerably in error.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America