The main objective of this study is to determin the uniformity (homogen- eity) of soil parent material in the areas under study (Shlalat, Khorsebad, Baashiqa, Talkeef, Batnaya, and Telsqeff) which represented by one pedon in each location . A complete morphological description has been done on these pedons, a soil samples have taken up to depth (120cm). Soil texture was measured by hydrometer method, and the total sand was separated by precipitation and decantation technique; and fractionated in to sand (non-clay fraction) size distribution as fllow :
1- (1-2mm) very coarse sand.
2- (0.5-1mm) coarse sand.
3- (0.25-0.5mm) medium sand.
4- (0.10-0.25mm) fine sand.
5- (0.05-0.10mm) very fine sand.
Percentage of each fractions were calculated on the basis of soil weight. The cumulated non-clay (sand) fractions distribution for each horizon of each pedon was drawn. The ratio of fine sand to total sand and ratio of fine sand to coarse sand were calculated for all horizons of studied pedons. Finally, the mineralogical analysis was used in this study on the Quartz mineral determination in very fine sand fraction (50-100µm) by XRD.
The results indicated generally, that the studied pedons were shown a homogeneity in their parent materials in both methods (cumulative curve and ratio of each of fine sand to total sand ;and fine sand to coarse sand) among all horizons underlying surface horizons only; this is due to Authogeneic processes which included dust fall added by Aeolian sediments. However, the method of the ratio of fine sand to total sand had obvioused the best method in this study for arid to semi-arid regions. Moreover, the mineralogical observation had reveled a very clear homogeneity test in this studied soils at the range of standard deviation about less than (<21%). And from this rare method of homogeneity (mineraltest); concluded that the components of dust fall addition were other than Quartz mineral which may be Feldspars and/or Calcits.
Finally, we can grouped a study area genetically (parent material formation) into four different parent material sources which contributed in their pedons formation as: groups (Shlalat & Batnaya); (Baashiqa & Talkeef); pedon (Khorsebad) and pedon (Telsqeff) respectively.