Abstract
Soil water retention considering matric and osmotic potentials is a prerequisite for understanding saline irrigation and water stress in arid and semi-arid regions. The experiment was conducted to study salinity effect on pF, evapotranspiration and plant water stress. It was assumed that soil water potential is the sum of the matric and osmotic potentials. The experiment of plant water stress using Komatsuna was carried out in a growth chamber (phytotron) at 25°C temperature and a relative humidity of 70%. The results exhibit that soil salinity increased after each irrigation causing an increase in osmotic potential component of the total soil water potential. The evapotranspiration decreased as salt concentration increased which is due to higher osmotic potential component. Higher salt concentration could increase pF so that availability of water to plants decreased. The results of the experiment showed that the osmotic potential was the dominant component of the adjusted pF (including osmotic potential component) in saline water treatments. The osmotic potential component value also contributed in the wilting of the plants. The results of the study suggest that the concept of pF value including matric and osmotic potential components can be used in applying soil water retention curves of salt affected soils for the development of lands in arid and semi-arid regions.
