الفهرس 
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Abstract
Two experiments were conducted to study the interaction effect of irrigation water quality and organic residual on water movement and some soil properties. The first experiment (columns experiment) was conducted at the laboratory of Soils Dept., Fac., Agric., Mansoura Univ and aimed mainly to study the influence of salinity stress by low-quality water and organic residuals on water movement (hydraulic properties) and some soil properties in within alluvial soils. The second experiment (pot experiment) was conducted at the experimental station of Fac., Agric., Mansoura Univ to investigate the interaction effect between irrigation water quality and organic residuals on water movement and some soil properties in two different alluvial soils. Treatments: The experiment involved 12 treatments representing all possible combinations between: Two texture types of an alluvial soil Clay loamy soil (S1)Loamy soil (S2)Two types of irrigation water: Tap water (I1) Agricultural drainage water (I2) Three types of organic residuals Control (C0) Rice straw compost (C1) Rice straw compost biochar (C2). Soil measurements: Soil bulk density (ρb)and porosity (E) Hydraulic properties. Plant measurements: Fresh weight (g pot-1) Dry weight (g pot-1) The results obtained could be summarized as follows:- 1-The first experiment (columns).Results showed that applying both RSC and RSCB increased soil’s resistance against negative effect of low-quality water, not only that, but it improves soil quality properties. Furthermore, the addition of organic residuals in particular RSCB caused an increase of the soil hydraulic properties i.e. saturated hydraulic conductivity (Ks), unsaturated hydraulic conductivity K(θV), specific fluid flux (q) and intrinsic permeability (k) as a result of the positive change in soil bulk density (ρb), mean pore diameter (d) and porosity (E).Based on these results, the two types of treated rice straw could improve soil resistance against degradation caused by low-quality water irrigation through improving aggregation process, soil structure and water movement across soil matrix.2-The second experiment (pots).Under alluvial clay loamy soil irrigated by tap water; the highest mean values of fresh and dry weights of lettuce plant at both studied growth stages were realized due to the addition of RSCB followed by RSC treatment, while the lowest mean values were recorded with C0 treatment (without organic residual application), where treatments sequence from top to less was the S1I1C2> S1I1C1> S1I1C0. Also this trend was found under irrigation by agricultural drainage water, where treatments sequence from top to less was the S1I2C2> S1I2C1> S1I2C0.Although the trend of the investigated organic residuals effect on mean values of fresh and dry weights of lettuce plant under irrigated by poor water looks like its effect under irrigation by tap water, the mean values of fresh and dry weights of lettuce plant under tap water is higher than under agricultural drainage water because of the adverse influence of saline water. The alluvial loamy soil has the same behavior of clay loamy soil where, except dry weight at 80 day under which has un obvious trend.Furthermore, both investigated organic residuals alleviate the adverse influence of agricultural drainage water and enhance lettuce growth parameters under irrigation by degraded waters.CONCLUSION Accordingto the finding of this investigation, the application of organic residuals )compost and biochar) has been proved to be superior treatments in resistance of soils and plant to the adverse effect of low-quality water by increasing the soil macro-pores and hydraulic conductivity (saturated and unsaturated) and enhancement soil properties for agricultural proposes.