The Interactive Effects of Saline Irrigation Water, Potassium and Gypsum on Mineral Nutrient Accumulation and Grain Protein Content of Wheat ( Triticum aestivium L . )

摘要

This study was conducted to determine the effect of saline water, potassium and gypsum application on accumulation of some mineral nutrients in plant and grain protein content in wheat ( Triticum aestivium L. cv. Tajan ), during 2002-2003 growing season. For this purpose, five levels of electrical conductivity of irrigation water namely 0.8 (well water), 3, 6, 9 and 12 dS m^-1 (mixture of Caspian Sea water and well water), four levels of potassium (0, 0.4, 0.8 and 1.2 g K₂O pot^-1) and three levels of gypsum (0, 1.75 and 3.50 g pot^-1) were applied in a Completely Randomized Factorial Design in pot experiment. The results showed that with increasing salinity of irrigation water, amount of sodium accumulation in leaves, roots and grain protein content increased, potassium content and K⁺/Na⁺ in roots and leaves decreased, significantly (p+ and K⁺/Na⁺ decreased in leaves and roots. Potassium application increased the amount of potassium and K⁺/Na⁺ in roots and leaves, and gypsum application increased the calcium accumulation and reduced the Na⁺/Ca²⁺. Grain protein content, K⁺ and K⁺/Na⁺ increased with interactive effects of potassium and salinity. Simultaneous application of potassium and gypsum increased the accumulation of K⁺ and Ca²⁺ in leaves and reduced Na⁺ in roots. The amount of grain protein increased in lower potassium treatments, but decreased in higher amounts of K⁺.