Variation of the Particle Size Distribution for the Soil in the Middle Euphrates Regions

Abstract

The study locations were chosen within the central Euphrates regions, which include the provinces of (Babylon, Diwaniyah, Karbala, Najaf, and Muthanna), which lie between longitudes 31.2926 to 32.9055 north and latitudes 44.0332 to 45.3845 east by UTM system. Fifteen pedons were discovered, three pedons in each province, two for planted soil and one for uncultivated soil, and their horizons were described in a morphological and fundamental manner, and their coordinates were determined. Samples were obtained from each horizon, saved and brought to the laboratory for the necessary laboratory measurements. The results of the morphological description showed that the soils of the Middle Euphrates regions are calcareous sedimentary newly formed with flat topography, and the natural vegetation of the Bermuda grass, cogongrass and Alhagi in its soil. As for the color of the soil, the results indicated that the color is homogeneous in wavelength and the difference in intensity and purity of the color. Soils with fine and moderately fine textures were prevalent. It had an angular block structure in all the horizons of the cultivated soils, except for the uncultivated soils. Its construction was of the acute-angled block type, while the strength of the soil was varied in all cases and in all horizons. The results indicated that the size distribution of the soil separates is different, but the predominance of the silt separate, followed by clay and then sand. In terms of its variance, sand was the most variance, where its coefficient of variation ranged between 81.99 - 60.72%, followed by clay, whose coefficient of variation ranged between 47.02 - 29.32%. As for the silt, it was the least variance, where its coefficient of variation ranged between 17.49 - 11.10. These separates were distributed unnaturally, with negative and positive Skewness, and with a flat negative and positive distribution in most soil horizons and locations.