Twelve soil profiles representing four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, were selected to give some information about morphological, physical and chemical properties of some shale-derived soils and to identify the soil taxonomic units of these soils with a special reference to their suitability for agricultural use. The texture class of the studied samples differs from sandy loam, silty loam, clay loam and loam to clay with a finer texture in El-Kharga, Gharb El-Mawhub and El-Dakhla and a coarser one in El-Zaiyat. Most of these samples are moderate to extremely strong saline with moderate calcium carbonate and low organic matter in most locations. Gypsum content is low to moderate and tends to be lower in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of different soils are positively correlated to the fine particles content. Soil reaction (pH) tends to be slightly to moderately alkaline in most locations. Most soil samples have exchangeable sodium percentage (ESP) values less than 15%, except few soil samples at El-Kharga and El-Dakhla. Free iron oxide content ranged between 0.46 and 11.07 % and did not show any consistent distribution pattern in the studied locations. Based on the morphological and analytical soil properties, the studied soil profiles were classified according to Soil Taxonomy as: a) Typic Torriorthents, b) Vertic Torriorthents, c) Typic Haplosalids, d) Gypsic Haplosalids, e) Sodic Haplotorrerts and f) Typic Salitorrerts. According to land capability classification, most of the soils under consideration are placed in classes (П and Ш). Most of these soils are affected by high limitation of salinity and sodicity levels.

Twelve soil profiles representing four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, were selected to give some information about morphological, physical and chemical properties of some shale-derived soils and to identify the soil taxonomic units of these soils with a special reference to their suitability for agricultural use. The texture class of the studied samples differs from sandy loam, silty loam, clay loam and loam to clay with a finer texture in El-Kharga, Gharb El-Mawhub and El-Dakhla and a coarser one in El-Zaiyat. Most of these samples are moderate to extremely strong saline with moderate calcium carbonate and low organic matter in most locations. Gypsum content is low to moderate and tends to be lower in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of different soils are positively correlated to the fine particles content. Soil reaction (pH) tends to be slightly to moderately alkaline in most locations. Most soil samples have exchangeable sodium percentage (ESP) values less than 15%, except few soil samples at El-Kharga and El-Dakhla. Free iron oxide content ranged between 0.46 and 11.07 % and did not show any consistent distribution pattern in the studied locations. Based on the morphological and analytical soil properties, the studied soil profiles were classified according to Soil Taxonomy as: a) Typic Torriorthents, b) Vertic Torriorthents, c) Typic Haplosalids, d) Gypsic Haplosalids, e) Sodic Haplotorrerts and f) Typic Salitorrerts. According to land capability classification, most of the soils under consideration are placed in classes (П and Ш). Most of these soils are affected by high limitation of salinity and sodicity levels.

Eight soil profiles were chosen to represent some soils of four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, Egypt. Studies of the mineralogical composition of the sand fraction were performed to evaluate the origin, uniformity and weathering status of these soils. X-ray diffraction technique as well as transmission and scanning electron microscopy were also used to identify the clay mineral suits of these soils. The obtained data reveal that the texture class of the studied surface samples differs from sandy loam, silt loam and clay with a finer texture in Gharb El-Mawhub and El-Dakhla and a coarser one in El-Kharga and El-Zaiyat. Most of these samples are moderately to strongly saline with low calcium carbonate and organic matter in most locations. Gypsum content is low and tends to be free in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of these soils were found to be in accord with their fine particle content (clay and silt). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. The studied soils are classified according to Soil Taxonomy as: Typic Torriorthents, Typic Torrifluvents, Gypsic Haplosalids and Typic Haplosalids. Microscopic examination of the sand fraction reveals that the minerals of the light fraction are mainly dominated by quartz followed by calcite beside small amounts of feldspars. On the other hand, opaque minerals dominate the heavy fraction of all studied soils in most locations. The non-opaques are composed essentially of zircon, epidotes, pyroxenes, tourmaline and amphiboles and are present in relatively high amounts. Staurolite, rutile and garnet are found in pronounced amounts while kyanite and biotite are found in minor quantities. Uniformity and weathering ratios indicate that the soils are heterogeneous, either due to their multi-origin and/or to their formation from parent materials of heterogeneous nature. Thus, the soils are weakly developed, pedogenically young and are formed from different sources. Smectites (montmorillonite), kaolinites, illite and playgorskite are present in most cases. The predominant clay minerals of the shale deposit in El-Kharga oasis and El-Zaiyat plain are smectites (montmorillonite) with traces of illite and kaolinite. Clay separated from EL-Dakhla oasis is illite, playgorskite and kaolinite, while Gharb El-Mawhub soils have kaolinite as the dominant clay mineral, with small amount of sepiolite and chlorite in some samples. Interstratified minerals are detected in low amounts or as traces in some samples. Quartz and feldspars occur in the clay fraction of most samples in very small amounts.

Eight soil profiles were chosen to represent some soils of four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, Egypt. Studies of the mineralogical composition of the sand fraction were performed to evaluate the origin, uniformity and weathering status of these soils. X-ray diffraction technique as well as transmission and scanning electron microscopy were also used to identify the clay mineral suits of these soils. The obtained data reveal that the texture class of the studied surface samples differs from sandy loam, silt loam and clay with a finer texture in Gharb El-Mawhub and El-Dakhla and a coarser one in El-Kharga and El-Zaiyat. Most of these samples are moderately to strongly saline with low calcium carbonate and organic matter in most locations. Gypsum content is low and tends to be free in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of these soils were found to be in accord with their fine particle content (clay and silt). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. The studied soils are classified according to Soil Taxonomy as: Typic Torriorthents, Typic Torrifluvents, Gypsic Haplosalids and Typic Haplosalids. Microscopic examination of the sand fraction reveals that the minerals of the light fraction are mainly dominated by quartz followed by calcite beside small amounts of feldspars. On the other hand, opaque minerals dominate the heavy fraction of all studied soils in most locations. The non-opaques are composed essentially of zircon, epidotes, pyroxenes, tourmaline and amphiboles and are present in relatively high amounts. Staurolite, rutile and garnet are found in pronounced amounts while kyanite and biotite are found in minor quantities. Uniformity and weathering ratios indicate that the soils are heterogeneous, either due to their multi-origin and/or to their formation from parent materials of heterogeneous nature. Thus, the soils are weakly developed, pedogenically young and are formed from different sources. Smectites (montmorillonite), kaolinites, illite and playgorskite are present in most cases. The predominant clay minerals of the shale deposit in El-Kharga oasis and El-Zaiyat plain are smectites (montmorillonite) with traces of illite and kaolinite. Clay separated from EL-Dakhla oasis is illite, playgorskite and kaolinite, while Gharb El-Mawhub soils have kaolinite as the dominant clay mineral, with small amount of sepiolite and chlorite in some samples. Interstratified minerals are detected in low amounts or as traces in some samples. Quartz and feldspars occur in the clay fraction of most samples in very small amounts.

Eight soil profiles were chosen to represent some soils of four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, Egypt. Studies of the mineralogical composition of the sand fraction were performed to evaluate the origin, uniformity and weathering status of these soils. X-ray diffraction technique as well as transmission and scanning electron microscopy were also used to identify the clay mineral suits of these soils. The obtained data reveal that the texture class of the studied surface samples differs from sandy loam, silt loam and clay with a finer texture in Gharb El-Mawhub and El-Dakhla and a coarser one in El-Kharga and El-Zaiyat. Most of these samples are moderately to strongly saline with low calcium carbonate and organic matter in most locations. Gypsum content is low and tends to be free in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of these soils were found to be in accord with their fine particle content (clay and silt). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. The studied soils are classified according to Soil Taxonomy as: Typic Torriorthents, Typic Torrifluvents, Gypsic Haplosalids and Typic Haplosalids. Microscopic examination of the sand fraction reveals that the minerals of the light fraction are mainly dominated by quartz followed by calcite beside small amounts of feldspars. On the other hand, opaque minerals dominate the heavy fraction of all studied soils in most locations. The non-opaques are composed essentially of zircon, epidotes, pyroxenes, tourmaline and amphiboles and are present in relatively high amounts. Staurolite, rutile and garnet are found in pronounced amounts while kyanite and biotite are found in minor quantities. Uniformity and weathering ratios indicate that the soils are heterogeneous, either due to their multi-origin and/or to their formation from parent materials of heterogeneous nature. Thus, the soils are weakly developed, pedogenically young and are formed from different sources. Smectites (montmorillonite), kaolinites, illite and playgorskite are present in most cases. The predominant clay minerals of the shale deposit in El-Kharga oasis and El-Zaiyat plain are smectites (montmorillonite) with traces of illite and kaolinite. Clay separated from EL-Dakhla oasis is illite, playgorskite and kaolinite, while Gharb El-Mawhub soils have kaolinite as the dominant clay mineral, with small amount of sepiolite and chlorite in some samples. Interstratified minerals are detected in low amounts or as traces in some samples. Quartz and feldspars occur in the clay fraction of most samples in very small amounts.

Eight soil profiles were chosen to represent some soils of four locations (El-Kharga oasis, EL-Dakhla oasis, El-Zaiyat plain and Gharb El-Mawhub) in the New Valley governorate, Egypt. Studies of the mineralogical composition of the sand fraction were performed to evaluate the origin, uniformity and weathering status of these soils. X-ray diffraction technique as well as transmission and scanning electron microscopy were also used to identify the clay mineral suits of these soils. The obtained data reveal that the texture class of the studied surface samples differs from sandy loam, silt loam and clay with a finer texture in Gharb El-Mawhub and El-Dakhla and a coarser one in El-Kharga and El-Zaiyat. Most of these samples are moderately to strongly saline with low calcium carbonate and organic matter in most locations. Gypsum content is low and tends to be free in El-Kharga and El-Zaiyat. The cation exchange capacity (CEC) values of these soils were found to be in accord with their fine particle content (clay and silt). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. The studied soils are classified according to Soil Taxonomy as: Typic Torriorthents, Typic Torrifluvents, Gypsic Haplosalids and Typic Haplosalids. Microscopic examination of the sand fraction reveals that the minerals of the light fraction are mainly dominated by quartz followed by calcite beside small amounts of feldspars. On the other hand, opaque minerals dominate the heavy fraction of all studied soils in most locations. The non-opaques are composed essentially of zircon, epidotes, pyroxenes, tourmaline and amphiboles and are present in relatively high amounts. Staurolite, rutile and garnet are found in pronounced amounts while kyanite and biotite are found in minor quantities. Uniformity and weathering ratios indicate that the soils are heterogeneous, either due to their multi-origin and/or to their formation from parent materials of heterogeneous nature. Thus, the soils are weakly developed, pedogenically young and are formed from different sources. Smectites (montmorillonite), kaolinites, illite and playgorskite are present in most cases. The predominant clay minerals of the shale deposit in El-Kharga oasis and El-Zaiyat plain are smectites (montmorillonite) with traces of illite and kaolinite. Clay separated from EL-Dakhla oasis is illite, playgorskite and kaolinite, while Gharb El-Mawhub soils have kaolinite as the dominant clay mineral, with small amount of sepiolite and chlorite in some samples. Interstratified minerals are detected in low amounts or as traces in some samples. Quartz and feldspars occur in the clay fraction of most samples in very small amounts.

The content of various forms of free iron (Fe) oxides in ten soil profiles, sampled to represent different locations in upper Egypt (Tushka, Wadi El-Nuqra, El-Kharga and El-Dakhla), was studied using selective extraction methods for whole soil samples and their size fractions (clay, silt and very fine sand). The effect of removing free iron oxides on soil color was also examined. The studied soils have a texture class, in most locations differs that from sand to loamy sand with a finer texture in El-Dakhla and a coarser one in other locations. Most of these soils are free to slightly saline with low calcium carbonate and organic matter (OM). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. According to Soil Taxonomy, the studied soils are classified as: Typic Torripsamments, Typic Torriorthents, and Typic Haplotorrerts. The results reveal that the oxalate-extractable iron (Feo), the dithionite-citrate-bicarbonate-extractable iron (Fed) and total Fe (Fet) in the whole soil samples range from 0.05 to 2.41, from 2.73 to 13.60 and from 4.37 to 42.84 g/kg, respectively. In the clay fraction they ranged from 0.34 to 16.41, from 13.64 to 45.82 and from 45.85 to 139.02 g/kg, respectively, whereas in the silt fraction, they vary from 014 to 19.22, from 3.35 to 66.52 and from 12.78 to 80.24 g/kg, respectively. In the very fine sand fraction, they ranged from 0.04 to 2.48, from 0.63 to 19.30 and from 5.10 to 32.92 g/kg, respectively. The silt fraction contains the highest values of (Feo) for El-Dakhla samples followed by the clay fraction, whereas Tushka samples show the lowest values. In soil profiles of Tushka and El-Dakhla, the silt fraction followed by the clay fraction contains the highest values of Fed, while Wadi El-Nuqra and El-Kharga soils have its lowest values. The clay fraction of Wadi El-Nuqra shows the highest amount of Fet. On the other hand, Tushka whole soil samples and their fractions have the lowest values of Fet. The amount of Fet increases with decreasing the size of soil particles. The activity ratio (Feo/Fed) ranges from 0.01 to 0.46 in the whole soil samples, from 0.01to 0.44 in the clay fraction, from 0.005 to 0.45 in the silt fraction and from 0.01 to 0.33 in the sand fraction. El-Dakhla soils contain the highest activity ratios in the studied soils, resulting in more domination of amorphous Fe oxides than other locations. Tushka and Wadi El-Nuqra samples contain the highest amounts of crystalline Fe oxides in the studied soils. High amounts of silicate Fe are found in Wadi El-Nuqra and New Valley samples compared with those of Tushka ones. Generally, the removal of free iron oxides from the whole soil samples and their fractions resulted in changes in their color and redness rating (Rr), especially for Tushka samples.

The content of various forms of free iron (Fe) oxides in ten soil profiles, sampled to represent different locations in upper Egypt (Tushka, Wadi El-Nuqra, El-Kharga and El-Dakhla), was studied using selective extraction methods for whole soil samples and their size fractions (clay, silt and very fine sand). The effect of removing free iron oxides on soil color was also examined. The studied soils have a texture class, in most locations differs that from sand to loamy sand with a finer texture in El-Dakhla and a coarser one in other locations. Most of these soils are free to slightly saline with low calcium carbonate and organic matter (OM). Soil reaction (pH) tends to be mildly to moderately alkaline in most locations. According to Soil Taxonomy, the studied soils are classified as: Typic Torripsamments, Typic Torriorthents, and Typic Haplotorrerts. The results reveal that the oxalate-extractable iron (Feo), the dithionite-citrate-bicarbonate-extractable iron (Fed) and total Fe (Fet) in the whole soil samples range from 0.05 to 2.41, from 2.73 to 13.60 and from 4.37 to 42.84 g/kg, respectively. In the clay fraction they ranged from 0.34 to 16.41, from 13.64 to 45.82 and from 45.85 to 139.02 g/kg, respectively, whereas in the silt fraction, they vary from 014 to 19.22, from 3.35 to 66.52 and from 12.78 to 80.24 g/kg, respectively. In the very fine sand fraction, they ranged from 0.04 to 2.48, from 0.63 to 19.30 and from 5.10 to 32.92 g/kg, respectively. The silt fraction contains the highest values of (Feo) for El-Dakhla samples followed by the clay fraction, whereas Tushka samples show the lowest values. In soil profiles of Tushka and El-Dakhla, the silt fraction followed by the clay fraction contains the highest values of Fed, while Wadi El-Nuqra and El-Kharga soils have its lowest values. The clay fraction of Wadi El-Nuqra shows the highest amount of Fet. On the other hand, Tushka whole soil samples and their fractions have the lowest values of Fet. The amount of Fet increases with decreasing the size of soil particles. The activity ratio (Feo/Fed) ranges from 0.01 to 0.46 in the whole soil samples, from 0.01to 0.44 in the clay fraction, from 0.005 to 0.45 in the silt fraction and from 0.01 to 0.33 in the sand fraction. El-Dakhla soils contain the highest activity ratios in the studied soils, resulting in more domination of amorphous Fe oxides than other locations. Tushka and Wadi El-Nuqra samples contain the highest amounts of crystalline Fe oxides in the studied soils. High amounts of silicate Fe are found in Wadi El-Nuqra and New Valley samples compared with those of Tushka ones. Generally, the removal of free iron oxides from the whole soil samples and their fractions resulted in changes in their color and redness rating (Rr), especially for Tushka samples.

Ten surface soil samples were selected to represent some soil types of four prominent locations (Tushka, wadi El-Nuqra, El-Kharga and El-Dakhla) in Egypt. The aim was to study the effect of removal of free iron oxides from the whole soil samples and their size fractions (clay and silt) on the cation exchange capacity (CEC) of these soils. The obtained data reveal that the texture class of the studied surface samples differs from sand to sandy loam with a finer texture in El-Dakhla and a coarser one in El-Kharga. Most of these samples are none to slightly saline with low calcium carbonate and organic matter in some locations. Soil reaction (pH) tends to be moderate to alkaline in most locations. Based on the morphological, physical and chemical soil properties, the studied soils are classified down to the sub-group level according to Soil Taxonomy as: Typic Torripsamments, Typic Torriorthents and Typic Haplotorrerts. The removal of free iron oxides from the whole soil samples and their fractions (clay and silt) caused an increase in the cation exchange capacity (CEC) of most studied soils. For the whole soil samples, the highest increase in the CEC was recorded for El-Kharga and the lowest one for Tushka. In most soil samples of Tushka, silt fraction had the highest increase in the CEC, whereas El-Kharga silt fraction gave the lowest increase. Highest values of CEC for El-Kharga soils and lowest ones for wadi El-Nuqra were obtained after removing free iron oxides from the clay fraction of these soils.

Forty-two soil profiles were selected to represent an area of 2500 feddans of desert sandy soils in Tushka, South Valley, Egypt. The area is located on the right side of Abu-Simbel/ Aswan road (Km 15- Km 20) north of Abu-Simbel City. Morphological characteristics of the area were described. Soil samples were collected to study physical and chemical properties of soils, soil development, classification and land evaluation for agricultural purposes. Results of the morphological rating scale indicate that the soils have relatively a moderate distinctness and a slight development stage with mostly close relative horizon distinctness (RHD). Relative profile development (RPD) values indicate clear variations between horizons that reflect great obvious heterogeneity of the soil parent materials with very slight profile development. The obtained data reveal that the texture class of the studied soils differs from sand to sandy loam. Most of soil profiles are none to slightly saline and have an exchangeable sodium percentage (ESP) of 15 %, sodium adsorption ratio (SAR) of 13 with low calcium carbonate (CaCO3) content. Gypsum and organic matter contents are generally very low and soil reaction (pH) tends to be moderate to alkaline. Sodium and sulphate ions dominate in soil solution. Based on morphological, physical and chemical soil properties, the soils under consideration were classified according to soil taxonomy down to the family level as: a) Sandy, mixed, hyperthermic, Typic, Lithic or Sodic Torripsamments, b) siliceous, hyperthermic, Typic or Lithic Quartzipsamments, c) coarse-loamy, mixed, hyperthermic, Typic or Lithic Torriorthents and d) coarse-loamy, mixed, hyperthermic, Typic Natrargids. Applying the fertility capability classification (FCC) system, the studied soils were classified as: Sdb (1), Sdb (2), Sdbs (1), Sdbs (2), Sdbsn (2), SLdb (1), SLdbs (1), SLdbsn (2), Ldb (2) and Ldbs (2). Most of the soils under study are suitable for irrigation. However, few soil profiles are not suitable for irrigation because they have severe to very severe limitations.