EFFECT OF WATER IRRIGATION QUALITY AND MULCHING ON SOME SOIL PHYSICALPROPERTIES UNDER DRIP IRRIGATION SYSTEM

A field experiment was conducted in Al-Raid Experimental station, Ministry of Water Resources, 20 km west of Baghdad, during autumn season 2008, in silt clay loam soil classified at Typic torriflvent, to study the effect of water irrigation quality, soil mulching on some physical properties under drip irrigation system. The Experimental design was Factorial Experiment with RCBD in three replicates. The study includes two factors: 1- Water quality, which includes three factors: a- Irrigation with river water (W-R) (1.1 ds. m (-1)). b- Irrigation with saline water (W-s) (4.5 ds. m (-1)). c- Alternate irrigation (W-A).2- Soil mulching includes two factors: a- Soil mulching with black polyethylene (M). b- With out mulching (W). The results can be summarized as follows: The irrigation treatments effected the soil physical properties at 0-20 cm depth. It was found that the MWD decreased to 0.603, 0.476 and 0.303 mm for all treatments respectively compared with the value of 0.65mm at the beginning of the experiment. Soil bulk density was effected by alternate and saline water treatments, the values were 1.33 and 1.39 Mgm . m(-1) respectively compared with the value of 1.30 Mgm . m(-1) at the beginning of the experiment, while the bulk density of the river water treatment was not effected.The saturated hydraulic conductivity effected by the irrigation treatments, it was 3.263, 2.547 and 1.677 cm . hr(-1) for all treatments respectively compared with 3.30 cm hr at the beginning of the experiment. The soil penetration effected by irrigation treatments. It was found that the values were 1.61, 1.82 and 1.93 Kg . cm(-1) for all treatment at 25% moisture level compared with the value 1.40 Kg . cm(-1) at the beginning of the experiment. Mulching did not appears any significant difference in mean wet diameter, hydraulic conductivity and density, but significant difference in penetration.