جستجوی مقالات مرتبط با کلیدواژه « مکش ماتریک خاک » در نشریات گروه « آب و خاک »

The effects of soil matric suction and salinity were investigated on the yield components and root development of the corps, wheat and bean within greenhouse conditions. The results showed that yield components and root dry weights of wheat and bean increased with increase in matric suction (from 2kPa) and reached their maximum values at suctions of 6-10 kPa. At suctions higher than 10kPa and under EC≤8dSm-1 for wheat vs. EC≤4dSm-1 for bean, all the yield components of wheat and bean (except for 1000-kernel weight) decreased, while under higher salinities, their values remained nearly the same. At suctions higher than 10kPa and under all salinity levels, 1000-kernel weights of wheat and bean remained nearly constant. The salinities of low to medium levels did not clearly affect yield and root development of either plant. Minimum root densities of wheat and bean occurred at suction 6kPa while at other points of suction (2, 10 and 33kPa), their values almost corresponded with each other. Salinity did not clearly affect wheat and bean root densities. Wheat shoot-root ratio decreased with matric suction (up to 10kPa) under EC≤8dSm-1, while under higher salinities, this ratio increased with suctions. At 10kPa suction, weight ratio values approached each other, then remained nearly constant at higher suctions. The results finally revealed that plant response to salinity stress depends on aeration conditions in the root zone and the deficit in soil aeration can amplify the salinity stress.

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.