Abstract

Irrigated soils suffer in arid and semi-arid regions of the world, from the problem of the accumulation of salts for not using sufficient washing water in quantity and quality to remove the added salts from the soil body, wrong irrigation practices and poor quality and quantity of irrigation water, there is no effective drainage system that contributes to increasing soil salinity. This field experiment was conducted to study the effect of the time period between washings, wash water quality, addition percentage on the values of bulk density and weighted drop rate of soil affected by salinity. As 3 breaks were specified between washes (5 and 10 15 days), two types of washing water (4 and 8 dS m-1 ), and two percentages for addition (25 and 50%). Soil field operations were conducted in order to apply all study treatments. The bulk density and weighted mean diameter were estimated for depths 0-25, 25-50, 50-75 and 75-100 cm after the end of soil washing. The results showed that the time period exceeded 10 days, the quality of water was 4 dS m1 and the percentage of addition was 50% on reducing soil bulk density values, compared to other levels, the bulk density values increased with increasing soil depth and they were 1.43, 1.52, 1.57 and 1.63 mg m-3 , for depths 0-25, 25-50, 50-75 and 75-100 cm respectively. As for the weighted average diameter values, the largest values appeared at the 15-day time period, the water quality of 8 dS m-1 and the rate of addition of 50%, compared to other levels. As the values decreased, the soil depth increased by 0.31, 0.22, 0.20 and 0.14 mm, for depths 0-25, 25-50, 50-75 and 75-100 cm, respectively.