HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ohki, K. Articles by Ulrich, A. Search for Related Content PubMed Articles by Ohki, K. Articles by Ulrich, A. Agricola Articles by Ohki, K. Articles by Ulrich, A.

Potassium Absorption by Excised Barley Roots in Relation to Antecedent K, P, N, and Ca Nutrition¹

In absorption studies with excised roots, the nutritional status of roots in relation to root growth has been difficult to assess prior to the absorption period. Since the antecedent nutrition greatly influences the subsequent K absorption, it is important to assess the nutritional status of roots undergoing ion absorption. Therefore, this study was initiated to determine the influence of antecedent nutrition of K, P, Ca, NO₃-N, and overall salt status of excised barley (Hordeum vulgare) roots on K absorption.

Assessment of the nutritional status of the plants was made by comparing the analytical results of the excised roots to the corresponding critical nutrient value of 13.5 meq, 4.5 mmol, 2.9 meq, and 2.5 meq kg_-1 fresh wt, for K, P, Ca, and NO₃-N, respectively.

Under severe K deficiency, excised barley roots absorbed less K than comparable roots slightly deficient in K. Losses of K to the absorbing solution occurred from roots with high endogenous K. Excised roots from Pdeficient plants, low in endogenous K, absorbed less K than roots low in endogenous K with adequate P. Nitrogen deficiency alone did not increase the capacity for K absorption. Calcium deficiency suppressed K uptake primarily as a result of high endogenous K in Ca deficient roots. A combination of N deficiency and low endogenous K increased the capacity for K absorption. Low salt plants however, had the largest capacity to absorb K.

Key Words: Endogenous salt • Critical nutrient levels

² Associate professor, Department of Agronomy, University of Georgia, Experiment, GA 30212 and plant physiologist, Department of Soils and Plant Nutrition, University of California, Berkeley, CA 94720, respectively.

Received for publication May 20, 1974.