Effects of Single and Mixed Ion Solutions on Hydraulic and Physical Properties of a Clay Soil

摘要

In this work, the influence of solute concentration of two types of electrolyte solutions single-ion (Na) and mixed-ion (Na-Ca) systems on hydraulic and some physical properties of a clay soil was investigated. Saturated hydraulic conductivity (HC) declined noticeably using lower solute concentration in single ion system. The highest reduction in HC was observed at 250 mole_c m~(-3) solute concentration. Application of high solute concentration of single-ion system reduced meanweight diameter (MWD) to less than half of the control treatment (0.16 mm compared with 0.33 mm). Resistance to penetrometer increased with decreasing solute concentration. In mixed-ion system the MWD was increased whereas the resistance to penetrometer was decreased. HC values ranged from 6.5 x 10~(-4) to 9.0 x 10~(-4) mm s~(-1) in mixed ion system compared with 7.2 x 10~(-4) to 13.0 x 10~(-4) mm s~(-1) in single-ion system. The improvement of some physical properties in mixed-ion solution treatment is attributed to the presence of calcium ion that usually acts as amendment to sodium-affected soil. Soil HC showed lower values at low solute concentrations.