Studies on the buffer action of roots of rice, wheat and barley : (1) The difference in the various zones of the roots

1. The adjacent segments of excised roots were separately submerged in acid wellwater (e. g. pH 3.0, 3.4, or 4.0) for 20 hours. The pH of the wellwater was measured by the chinhydron electrode method at the beginning and end of every experiment. 2. At the end of every experiment the pH value usually reverted in the nutral (pH 7) direction by the buffer action of roots. 3. The buffer action was highest in the apical segment of the root and decreased in those more remote. 4. The buffer action differed with the species or varieties of the plants.