Impact of cation ratio structure stability (cross)‎ on the hydraulic conductivity saturation and clay dispersion for some calcareous soils in North Iraq

Abstract EN

In order to study the Impact of cations ratio of structure stability (CROSS) instead of SAR concept on the hydraulic conductivity saturation and clay dispersion for some calcareous soils in north Iraq for this purpose PVC plastic columns with an inner diameter (0.105) m and length (0.25) m were filled with soil samples were selected from two sites from Nineveh governorate Tell Abta (Sandy clay loam) and Rabia (clay loam), until (0.15)m and with bulk density (1.33) Mg.

m-3, CROSS solutions were prepared (0, 6, 8.4, 11.2 and 15.4).

(mmolC l-1)1/2with a constant SAR value (1.2) (mmolC l-1) 1/2with using (0.1M) chlorides electrolytic solutions (Na+, K+, Ca+2, and Mg+2).

The columns were wetted by capillary rise and for three wetting and drying cycles, to measure the water saturation hydraulic conductivity and the optical density (dispersion).

The results indicated that the addition of increased levels of potassium CROSS in electrolyte solutions from (0 - 15.4) (mmolC l-1)1/2.

caused increase in mono ionic adsorption (K+ and Na+) and a decrease in the saturation Hydraulic conductivity from (0.099) to (0.050) and (0.067) to (0.036) cm min -1 with a determination factor of (R2) of (0.86) and (0.94) for Tal Abta and Rabia, respectively.

The results also indicated that there was an increase in the optical density values of soil suspensions by 22.9% and 16.7% for Tal Abta and Rabia, respectively.