Effect of Soil Salinity on the Wheat and Bean Nutrients in Low Matric Suctions

In this study the effects of soil matric suction (2−33 KPa) and salinity (EC: 0.7−8 dSm-1 for bean and 2−20 dSm-1 for wheat) on the wheat and bean nutrient concentrations in two sandy loam and clay loam soils at green house condition was considerd. The potassium concentration increased and sodium decreased with matric suction in both plants. The nitrogen and calcium concentrations of bean and wheat increased with matric suctions and reached their extreme values at suctions 6-10 KPa. Concentration of nitrogen reduced and concentration of calcium remained nearly constant at higher suctions. The maximum concentration of iron and zinc were at suction 2KPa in both plants. As matric suction increased from 2 to 6 KPa, iron and zinc decreased strongly and remained nearly constant at higher suctions in both soils. Salinity increased concentrations of iron and calcium and reduced concentration of potassium in both plants. While it did not affect concentrations of nitrogen, sodium and zinc. The low soil matric suctions amplified the salinity stress due to aeration deficit. Also comparing two plants showed that because of high sensitivity of bean to stresses, changes of its nutrient concentrations under different levels of salinity and matric suction were greater than wheat.