Chloride content of onion roots and their adhering soil under irrigation with saline drainage water

Water depletion by plants in saline soils leads to the accumulation of salts in the soil in the close vicinity of the roots (= rhizopheric soil). CI−/l. After a period of 4 days water depletion the Cl–contents of 2,5 to 4, s me CI−/ 100 g soil were found in the rhizospheric soil of onions immediately after a water application, when irrigated with water containing 13 to 52 me Cl–content increased in the rhizospheric soil 3‐4 fold up to 12 me CI−/100 g soil corresponding to a CI–concentration in the rhizospheric soil solution of 800 me Cl‐L The differences between the irrigation treatments were small. The CI–contents of the roots in this experiment varied from 1,2‐1,9 me CT/g DM. When expressing the Cl–contents in terms of the cell sap of the roots, CI–concentrations of 1OC‐200 me CI−/I cell sap were abtained at a root water content of 90 %. Assuming a decrease in the root water contents to 70 % after a water depletion period of 4 days. CT‐concentrations of 500‐800 me Cl‐ll cell sap are obtained, which corresponded to CI‐concentrations determined in the rhizospheric soil solution.