Relationship between plant responses to high Na and ameliorative effects of supplemental K and Ca

ABSTRACT

The ameliorative effects of supplemental potassium (K) and calcium (Ca) were investigated from the viewpoint of water and nutrient status. Sodium (Na) stress resulted in poor water status in barley, maize and kidney bean and nutrient imbalance in all species, with small effects observed in soybean and kidney bean. Supplemental K and Ca effectively improved plant growth, especially in eggplant, green pepper, Chinese radish and spinach. Supplemental K or Ca ameliorated the nutrient status of all species. Supplemental Ca showed the greatest effect on growth improvement, increasing not only Ca concentration but also K concentration. However, maize and kidney bean could not maintain adequate water status under Na stress and exhibited greater growth suppression. From these results, we concluded that supplemental K and Ca is effective for the growth amelioration of plant species in which high Na salinization induces nutrient imbalance but does not affect water status.

KEYWORDS:

• Ameliorative effect
• calcium
• NaCl stress
• nutrient imbalance
• potassium
• salinity
• water status

Funding

We thank the Ministry of Education, Culture, Sports, Science and Technology of Japan for supporting this study by the Global Center of Excellence Program.