ABSTRACT
The essential concern in farming practices for arid and semi-arid regions is to maintain, through some controlled irrigation schemes and within the constraints imposed by soil properties and water quality, the soil moisture stress at the lowest possible level. The irrigation interval is an important factor since the crop must respond to the force with which water is held in the soil and also to the osmotic effects caused by salinity, both of which vary over time. During the cropping season, demand of water to meet the irrigation needs of crops in the command area may not allow for additional water for leaching of salts. Plants compensate for reduced water uptake from the highly saline zone by increasing its uptake from the low salinity zone reducing the leaching fractions has only a small effect on the salinity of this upper rootzone, since this area is adequately leached during each irrigation.
