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A field study was conducted on 2 hectare area at Al- Rashid district, south of Baghdad to analyze the spatial variability of saturated hydraulic conductivity (Ks), initial infiltration rate (IR), Porosity (F) and bulk density (BD). Based on measured BD values Rosetta software was used in this study to estimate water retention parameters, water content at θ33 and θ1500 kPa and unsaturated hydraulic conductivity at 33 kPa(k33), 100 kPa(k100) and  1500 kPa(k1500) according to Van Genuchten-Mualem model.  Measured and predicted data were analyzed both statistically and geostatistically and, the results showed a strong to moderate spatial dependence for the studied characteristics. The spatial correlation values (r2) were obtained with a spherical model for Ks, θ33, θ1500, k33, k100   and k1500, an exponential model for IR, and a Gaussian model for F and BD. Ks increased significantly with increasing of IR (r2 = 0.49**) and decreased with increasing of F and BD, IR increased with decreasing of BD (r2 = -0.326*) and BD increased with increasing of F (r2 = 0.989 **). In general the spatial distribution was moderately skewed (-0.5 to 0.5) for the studied characteristics with pronounced kurtosis (>2.5). The limit distance for the search radius to estimating spatial dependency varied from 29.9 m for BD to 105 m for IR.

A field experiment was carried out during  the spring season 2020 at the University of Baghdad to study  the effect of the length and depth of the drip tape on  wetting  advance ofsubsurface drip irrigation system using Hydrus 2D/3D program. The site was planted with sunflower  in a clay loam texture. The drip tape was installed at 0.3m below soil surfacein two lengths; 20m and 40m. The experiment was designed according to the arrangement of split plotsdesign and  with three replications. The treatments were randomly distributed and planted with sunflower crop. The results showed that the moisture contents of the 20 mlength drip tape was higher compared with  the 40 m   drip tape length. Also, the length of the tape was superior in some components of the yield if the length of the drip tape exceeded 20 m in the character of the number of seeds in one disc, and the result was a significant superiority.

The research aims to study the effect of the difference in vegetation cover and land use on temporal and spatial distribution on soil texture, bulk density (BD), particles density (PD), porosity (P) and organic matter (OM). The area of Algadwal Algharby in Karbala Governorate was chosen with an area of 14585 hectares. Sixty sites were randomly selected where disturbed and undisturbed soil samples were collected to a depth of 0-0.3 m. The disturbed samples were air dried, ground and passed through a 2 mm sieve for laboratory analysis while the undisturbed soil samples were collected by core sampler for bulk density determination. It was found that the dominant texture classes were (clay loam 35%, clay 20%, silt loam 13.3%, loam 10%, silty clay loam 10%, sandy clay loam 6.7%, silty clay 3.3% and sandy loam 1.7%). The results showed a spatial variation in the coefficient of variation (CV), skewness (SK), and spatial dependence (SD) for clay, silt, and sand were as follows: (39.15%, 0.176, 34.34%), (37.52%, 0.587, 27.29%), and (45.83%, 0.148, 34.17%) respectively. Vegetation cover did not show any effect on soil texture, with low coefficient of variation. The values of CV, SK and SD of bulk density, particles density, porosity and organic matter were (7.08%, -0.294, 25.18%), (2.09%, 0.146, 24.46%) (8.33%, -0.073, 29.23%) and (35.36%, - 0.866, 35.69%) respectively. The percent of OM content for different land cover were (1.4, 1.29, 1.24, 0.94)% for palm trees, crops, palm plus citrus trees and fallow land respectively as affected by plant cover diversity which intern affected the bulk density and porosity. These findings may be attributed to the presence of different root systems, type and amount of plant residues, organic matter content and agricultural practices. Values of the skewness and kurtosis coefficients (KU) are in agreement with the assumption of normality of spatial distribution. The results also showed moderate to strong dependence of the studied characteristics with the spherical model for clay, silt and sand and circular model for bulk density, particle density, porosity and organic matter.