Chloride and Tritiated Water Flow in Disturbed and Undisturbed Soil Cores

Columns of disturbed and undisturbed Eden, Maury, and Pembroke soils were eluted with CaCl 2 in tritiated water. The chloride was used as a substitute for nitrate since it is not affected biologically. The experiments were carried out to investigate the effects of natural soil structure on the flow of water and chloride. In all three soils flow was less stable in the undisturbed cores judging from the shape of the curve and the points of initial tritiated water and chloride breakthrough. Chloride moved through the undisturbed Eden and Maury soils faster than through the disturbed columns. Both soils exclude anions to a significant extent. In the Pembroke soil, which adsorbs anions, the chloride was retarded in the undisturbed column as compared to the disturbed column. The results suggest that field movement of water and anions is not described very well by columns of disturbed, packed soils.