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Laboratory equipment and calculation procedure to rapidly determine hysteresis of some soil hydrophysical properties under nonsteady flow conditions
Author(s) -
Sobczuk Henryk A.,
Plagge Rudolf,
Walczak Ryszard T.,
Roth Christian H.
Publication year - 1992
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19921550214
Subject(s) - water content , hysteresis , soil science , hydraulic conductivity , soil water , desorption , water flow , flow (mathematics) , adsorption , environmental science , geotechnical engineering , chemistry , geology , mechanics , physics , quantum mechanics , organic chemistry
Laboratory equipment was developed to measure nonsteady water potential and water content profiles in soil columns, with a high resolution in time and space. Moisture content was monitored using TDR‐miniprobes and water potential was measured with microtensiometers. Gradients were applied by controlling the water potential at the bottom of the soil column during adsorption and desorption with the aid of a ceramic plate. The described experimental setup was designed specifically to determine effects of hysteresis on the water content/water potential and water potential/hydraulic conductivity relationships in undisturbed soil samples. In addition, an algorithm to process the data and to calculate the above mentioned relationships is presented. The algorithm includes the smoothing of data with Bezier functions before the calculation of the moisture retention curves and the conductivity functions. Results obtained from an albic E‐horizon of a silty Luvisol are presented exemplarily to demonstrate the applicability of the proposed method in studying hysteresis effects.