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 Rengel, Z. Search for Related Content PubMed Articles by Rengel, Z. Agricola Articles by Rengel, Z.

Modeling Magnesium Uptake from an Acid Soil: III. Determination of Root Magnesium Concentration

Dep. of Plant Science, Waite Agricultural Research Inst., Univ. of Adelaide, Glen Osmond, S.A. 5064, Australia

*Corresponding author.

ABSTRACT

Research on the nutrient interactions in the rhizosphere of soil-grown plants would benefit from a reliable estimate of root-nutrient concentrations. Ryegrass plants (Lolium multiflorum Lam., ‘Wilo’) were grown for 35 d in a greenhouse on an acid Stough soil (coarse-loamy, siliceous, thermic Fragiaquic Paleudult) amended with three rates of CaO and two rates of MgCl₂. Careful washing of roots in water was followed by a digestion procedure involving HF. Root Mg concentration was corrected for soil contamination based on Ti content in the root tissue. Titanium-corrected root Mg concentrations were lower than root Mg concentrations calculated by multiplying shoot Mg concentrations of soil-grown plants by the ratio of root to shoot Mg concentrations of solution-grown plants. Regression analysis showed that the Barber-Cushman model overpredicted total Mg uptake when root Mg content was calculated either from Ti-corrected root Mg concentrations (2.88 and 2.39 times for 0 and 36 mg Mg kg^–1, respectively) or from root/shoot Mg concentration ratios in solution-grown plants (1.98 and 1.66 times for 0 and 36 mg Mg kg^–1, respectively). Partitioning of Mg between roots and shoots of ryegrass may be quite different in soil- and solution-grown plants.

Received for publication July 23, 1990.