EFFECTS OF SOIL SALINIZATION AND WATERLOGGING ON THE CONCENTRATIONS OF SOME MACRONUTRIENTS AND SODIUM IN CORN ROOT

Salinity and waterlogging are two abiotic stresses decrease plants yield. In this research, the effects of soil salinization and waterlogging having concentrations of calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na) and K:Na ratio in corn (Zea mays cv. single cross 704) root were studied under greenhouse conditions. A factorial experiment with two factors on the basis of completely randomized design with three replications was performed. The factors under study were: waterlogging duration in five levels (0, 2, 4, 8, 20 days) and soil saturate extract salinity in four levels (0.11, 2, 4, 8 dS/m). A loamy sand soil for plant growth substrate and NaCl salt for establishing the levels of salinity was used. The salinity and waterlogging factors were imposed simultaneously to the plants from the five-leaf stage of plant growth period. The plants were harvested 60 days after sowing and the concentrations of Ca, K, Mg and Na in corn root were determined by dry ashi method. The results showed that by increasing the level of NaCl salinity in the soil, the K concentration and K:Na ratio of corn root were decreased significantly but concentrations of Ca, Mg and Na in corn root were increased significantly. The Mg and Na concentrations of root in waterlogged conditions were significantly lower than that of non-waterlogged conditions but the K and Ca concentrations of root in waterlogged conditions were significantly greater than non-waterlogged conditions. However, the effects of soil waterlogging duration on the Ca, K, Mg and Na concentrations and Na:K ratio of root were dependent on the level of NaCl salinity in the soil. The results demonstrated that even short periods of soil waterlogging had considerable long-term effects on the concentrations of Ca, K, Mg and Na and K:Na ratio in corn root under saline and non-saline conditions.