pH control in nitrate uptake studies with excised roots

Abstract

In the investigation of NO 3 − uptake by excised roots, pH of salt solutions can be effectively controlled by periodic additions of a cation exchange resin, Amberlite IR-120, in the H + form. This method of pH control provides for the addition of H + to systems without an accompanying anion which might influence the absorption of NO 3 − . The resin appeared to provide a favorable buffering capacity during an extended period and the method was especially useful for NO 3 − uptake studies conducted at high root-to-solution ratios.