Plant Responses to Saline Substrates III. Effect of Nutrient Concentration on the Growth and Ion Uptake of Hordeum Vulgare During a Sodium Chloride Stress

Abstract

Sodium chloride, at a concentration of 50 m-equiv/l, was applied to substrates with total nutrient concentrations of 0.4, 1.7, and 17 m-equiv/l. Treatment effects were studied over a 7-day period. Sodium chloride treatment increased the chloride and sodium contents, and decreased the potassium contents, of most plant parts at all nutrient levels. These changes in ion content were usually most pronounced at the lowest nutrient concentration. Large net losses of potassium were found from both the shoots and the roots of the sodium chloride -treated plants at the low nutrient level. Net potassium losses also occurred from the oldest leaf and sheath at the medium nutrient concentration. Salinity reduced growth at the low nutrient treatment only, and it is suggested that this was due to the drastically changed ion relationships of these plants. The findings emphasize the importance of the composition of the substrate to the tolerance of plants in a saline environment.