Cation exchange capacity of roots: Titration,sum of exchangeable cations,copper adsorption

The cation exchange capacity of roots (CECR) has been measured according to three different methods : titration of H‐roots with NaOH in the presence of CaCl₂, MgCl₂, or NaCl 0.1 N, saturation of roots with mixed Ca‐Mg‐Na solutions of eight different compositions and extraction of the adsorbed cations with copper, saturation of roots with Cu‐ions and extraction with HC1. Two types of roots were studied : roots of ryegrass (Lolium multiflorum Lm.) and roots of clover (Trifolium pratense L.)

The very good coincidence of the results from the three methods tends to prove the reliability of the experimental procedures. The simplicity and the reproducibility of the Cu‐method renders it recommendable in view of possible standardization of the methods in the future.