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Abstract West El-Mawhoob - Abo Monqar area is one of the virgin areas in the Western desert regarding their land, water resources and characteristics. This area is located at West El-Mawhoob and Abo Monqar, over approximately 450,000 feddan, Western desert, Egypt, At latitude between 25º 30\ 00\\ : 26º 05\ 00\\ N and longitude 27º 55\ 00\\ : 28º 15\ 00\\ E. Its elevation ranges between 100:300 meters above sea level. It is far about 600 km from Cairo. Aims of the present study are: 1- Assessing the dominant soil physical, chemical, and nutritional characteristics of the studied soil area, 2- Recognizing and classifying the main soil types, 3- Identifying the dominant clay minerals in the studied soils using X-Ray diffraction technique, 4- Estimating the capability and suitability of lands for different uses, 5- Creating a base maps for land resource management in a trial to encourage new settlements establishment. Climatologically, Dakhla oasis condition has a summer time with a temperature as high as the tropics. This makes it possible to grow tropical plants. While in winter time, the mild heat makes it favorable to grow the plants of temperate region. Geologicaly, El- Dakhla formation is dominant one that consisting of shale, marl and clay with intercalations of calcareous sandy and silty beds. It forms the major thickness of the succession that overlies the Duwi formation and underlies the Paleocene limestone beds along the scarp face from South El- Kharga to Abo Monqar. It also covers parts of the plain to the West of El- Dakhla and is exposed in the shallow depressions in the Abo Tartor-El Kharga flsh plateau. The tripartite subdivision of El- Dakhla formation in El- Kharga area keeps to gross lithological aspects throughout the various areas in El-Kharga- Abo Monqar stretch, and reflects repeated sea level fluctuations during its deposition. The chosen of West El-Mawhoob and Abo Monqar area may be called as ”The region of plateaus, depressions, plains, sand dunes and sand seas,” since these are the predominant features. However, they do not show any specific distribution pattern, the sand dunes (linear and barchan) and sand sea extend nearly in the West and South sides of the area. Water supply of the studied area at West El-Mawhoob and Abu-Monqar is derived from underground bed of sandstone. The ground water appears to flow to the surface entirely through artificial passages, i.e., bore – holes. Springs are few and far in between as controlled by the thickness, impermeability and extent of the red clay as proved by borings. The bore – holes may be conveniently divided into two classes: ancient and modern. Twenty soil profiles representing the main geomorphic units were described and soil samples were collected. The morphological description indicates that soils differ in depth from very shallow, shallow, moderately deep and deep. Also differ in texture from light, medium to heavy texture. Massive structure is the predominant ones. Soil color ranges from reddish yellow to brown . Analytical results were used to study soil characteristics, classification and land capability classification as follow: 1- Particle size distribution indicates that soils texture varies widely from sand to clayey. However, sandy texture is the most common textural class. Cation exchange capacity (CEC), field capacity (FC), wilting point (WP) and available water (AW) vary widely corresponding to texture classes and / or the presence of considerable amounts of amorphous inorganic materials. 2- Chemical composition of the soil saturation extract indicates that soils have different salinity levels ranging from low to extremely saline. Soil reaction varies widely from neutral to strongly alkaline. Organic matter content and total nitrogen are generally very low. CaCO3 content indicates slightly calcareous to extremely calcareous nature. Gypsum content is mostly detected in all soils with significant quantities. 3- Identified clay minerals content in the soils of the Pediplain is dominated with smectite group (montmorillonite) followed by kaolinite, while at the soil subsurface illite is recognized with less dominancy than kaolinite. In soils of secondary horizontal bedscarp, karstified platforms and solutional depression smectite group (montmorillonite) is dominated and followed by kaolinite. Clay minerals in the plateau soils are dominated by smectite group (montmorillonite) followed by kaolinite in the subsurface and deepest layers, while at the surface layers smectite group (montmorillonite) dominates, followed by chlorite, while kaolinite disappeared. Moreover, in the deeper layers, chlorite clay mineral is the most abundant and followed by kaolinite. 4- Application of soil taxonomy (2010) for classifying the studied soils indicated that they it were placed in one order, namely Entisols. Soil classification continued systematically to the sub greatgroup levels as follow: Typic Torrifluvents, Typic Torripsamments, Typic Torriorthents. Lithic Torripsamments, Lithic Torriorthents, Lithic Quartzipsamments and Typic Quartzipsamments. 5- Land productivity indix were calculated for all profiles and found to be ranged between 80.2 % for poor land productivity class (P4) and 19.8 % for fair land productivity class (P3) according to Sys et al. (1991-I). According to the soil properties, natural and environmental circumstances at the studied area, the following agricultural development plan can be Suggested: 1. Shallow and very shallow soils can be cultivated by shallow rooted fodder crops, 2. Deep and moderately deep soils can be cultivated by commonplants known in the adjacent areas to the studied one, 3. Cultivation of some cash crops that can adapt the environmental circumstances such as medicinal and aromatic plants, 4. All cultivated plants should be tolerant to salinity, drought and have low evapotranspiration and water requirements, 5. Cultivation of the wind breakers, to combat sand dunes encroachment, 6. Construction of some livestock industrial projects,to supply soils with organic manure, 7. Recycling of plant and animal wests to be resupplied to the soil for improving their chemical, physical and fertility properties, 8. Applying the agricultural biotechnology to avoid environmental contamination, 9. Dividing the area into sectors, each is served by groundwater wells taking into consideration to leave enough space between each well and another to avoid of the dropdown of water levels, 10. Improving the infrastructure at the study area. |