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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.

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.