The determination of water release characteristics of soil cores at low suctions

Abstract

A method is described for the rapid determination of water release characteristics in soil cores 75 mm diameter and 50 mm deep of field structure. A simple suction table system is described for drainage of samples to matric potentials between 0 to -20 kPa. The need for material to promote contact between sample surfaces and the suction medium is emphasised. The equilibration of samples on pressure plates to matric potentials < -20 kPa is also briefly considered. Guidelines are provided for the choice of equilibration pressures and saturation method. Errors associated with compactness, texture, wetting method, water content and disturbance at sampling and equilibration with the suction medium are discussed. Particular consideration is given to the determination of saturated water content and total porosity and their variation with soil type and condition. © 1988.