الفهرس 
Acknowledgement
Geology and geomorphology of EL-kharga OasisOnly 14 pages are availabe for public view
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Abstract
New Valley governorate is a part of the Western Desert, located at the southwestern part of Egypt, bordered by the Nile Valley at east, Libya at west, Sudan at south and El-Bahariya Oasis at north. It occupies )458,000 km2) and about 48 % of the total area of Egypt. It includes El-kharga, Baris, El-Dakhla, Gharb El- Mohob, Abou Monkar and El-Farafra oases.El-Kharga Oasis covers an area of about 4500 km2. It is bounded by longitudes 30° 27’ and 30° 47’ E and latitudes 24° 30’ and 26° 00’ N. The current study aimed to Evaluation of levels of fertility in some cultivated soils in El-kharga oasis through:1. Surveying the fertility of some of the cultivated areas in El-Kharga oasis.2.Determining the major physical and chemical characteristics of these area. 3. Determining the )N-P-K( nutrients status of the soils to suggest of the possible strategies for the cultivation of these soils.A total number of 100 sites of cultivated areas , Average sampling distance of 1.5 km. Surface and subsurface soil samples were collected. The study area were divided to four sections namely :1- North El-Kharga was represented by 28 sites. 2-Center of El-kharga area was represented by 30 sites.3-South El-kharga area was represented by 31 sites.4- Baris area was represented by only 11 sites.Data obtained could be summarized in the following:1. Soil texture: The texture of the four study areas as general was coarse the percentage of the sandy samples in north, central and south El-Kharga were 33.93, 45.00 and 17.74% respectively, no sand samples in Baris. Generally the percentage of the five texture clones namely sand, loamy sand, sandy loam, sandy clay loam and loam were 28.5, 31.5, 29, 10 and 1% respectively.2. The saturation percentage (SP%): The coarse texture of the surface 60 cm of the area reflected low saturation as 43.5% of the samples has saturation percentage less than 40%, 31% of the samples has saturation percentage 50% which may be associated with clay minerals in the shales of El-Kharga. The average of SP% was 38.93, 39.32, 47.13 and 48.36% for the soil of north El-kharga, center El-Kharga, south El-Kharga and Baris respectively, with general average of 42.63% . 3. Soil pH of El-Kharga ranges from 7.15 to 8.8. The data showed that 51.0% of the samples have pH values less than 8.0 and 39.5% of the samples were between 8.0 and less than 8.5 . in other word 90.5% of the samples were not sodic and only 9.5% of the samples were ≥ 8.5 or sodic 4. Electrical Conductivity (ECe):-The mean of surface and subsurface ECe value showed that 15% of the samples were less than 4 dSm-1, and 85%of the samples are saline. However 37% of the samples have dSm-1 between 4 to 8 or saline soil and 30% were between 8 to 16 dSm-1 or highly saline and 18%of the samples were very highly saline with dSm-1 >16 . Therefor 85% of the samples are saline with dSm-1 more than 4 dSm-1. Generally, the ECe ranged between 2.21 to 53.38 dSm-1 with average 10.47 dSm-1 in El-Kharga Oasis. The average ECe values 13.85, 11.75, 9.00 and 5.82 from north El-kharga to center El-Kharga, south El-Kharga and Baris respectively.5. Organic matter content:- The desert soil of El-Kharga have 0.00 to 0.76 % O.M.
6. Total carbonates (CaCO3): 66 % of the samples have CaCO3 less than 1 % and 30 % of the samples were between 1 and 2%. Only 5.5 % of the samples range 2.13 to 4.27 % CaCO3.7. Cation Exchange Capacity (CEC) of El-Kharga soils showed low Cation exchange capacity. CEC values ranges between 5.76 and 71.04 Cmol (+)/kg soil with average of 21.56 Cmol (+)/kg . The average CEC were 20 , 17.46, 23.64 and 28.49 in samples of north El-kharga to center El-Kharga, south El-Kharga and Baris respectively. The highest value were 71.04 Cmol (+)/kg for the loam samples .8. Sodium adsorption ratio (SAR) : The results showed 97% of samples were less than 15 and only 3% have SAR value more than 15. The average of SAR values were 7.12, 3.73, 4.74 and 5.05 for the samples of North El-kharga to Baris.9. Soluble Ions:
Soluble Cations :Soluble cations are generally high in El-Kharga soils matched the high ECe values. The value of the four soluble cations arranged in order of Ca, Mg, Na, K with average value of 15.17, 13.63, 12.56 and 4.44 Same order.
Soluble Calcium (Ca++): was found to ranged from 1.25 to 120 meq/l (or meq/kg) and at average of 15.09 meq/l which considered high concentration. The longitudinal average values distribution from north, central, south and baris show mean value of 18.88, 18.47, 10.81 and 8.18 in the same order. Soluble Magnesium (Mg++): The range of soluble Magnesium is 1.00-105.0 meq/l with average of 13.70. South direction except in the northern El-Kharga with average of 12.50, 15.72, 14.72 and 8.52meq/l.Soluble Sodium (Na+): Ranges was .93 to75.07 meq/l with average 12.56 meq/l North to south the average soluble sodium in meq/l was 17.33, 10.01, 11.55 and 10.22 meq/l. It is clear that North El-Kharga has the highest sodium only 25% of its samples have Na 5 meq/l and 75% of its samples 5meq/l. Soluble Potassium (K+): El-Kharga depression sectors has average of (3.42), (5.01), (4.25) and (6.2) through north to south with overall range of 0.48-18.8 and general average of (4.44), the value between practices is the average value. Soluble anions:-Soluble Chloride (Cl-): Soluble Chloride in El-Kharga depression ranged from 6.25 to 160 meq/l with average of 22.41 meq/l. The average values of soluble chloride from North to Baris are 25.89, 21.56, 23.33 and 13.28. Soluble Bicarbonate (HCO3-): Soluble Bicarbonate in El-Kharga ranged from 1.5-10.0 meq/l with average of 3.75 meq/l. The average of soluble Bicarbonate from Norther El-Kharga to Baris was 3.83, 3.56, 3.72 and 3.95. That almost no change in soluble Bicarbonate. Soluble Sulphates (SO4-2): Soluble sulfates in the soil of the New Valley is known to be high with average of 18.60 meq/l. The average from Norther El-Kharga to Baris was 22.5, 21.82, 14.28 and 12.09. 10- Available Nitrogen: The available nitrogen in El-Kharga Oasis ranged from 18.07 to 72.29 ppm with average 46.87 ppm. The average of available nitrogen was 36.02 ppm, 44.47 ppm, 55.71ppm and 56.17ppm in the soils of North El-kharga to Baris respectively. El-Kharga were 35.5% low and 64.5 % medium in available nitrogen. 11- Available phosphorus: The available Phosphorus in El-Kharga Oasis ranged from 2.14 to 39.84 with average 23.77.The average of range available Phosphorus 23.17 ppm , 24.29 ppm , 24.02 ppm and 23.77 ppm in the soils of North El-kharga to Baris . The samples have high available phosphorus or more than 15 ppm. Eighty six and half 86.5 % of the samples were high, 7% were medium and only 6.5% were low or less than 10 ppm. 12- Available Potassium: The results showed that 99% of high available potassium and only 1% is medium . The available Potassium in El-Kharga Oasis average was 349.01 ppm.CONCLUSION• The soils of El-Kharga is very poor in organic matter it need fertilization to improve nitrogen and nutrients availability, permeability, cation exchange capacity (CEC).•Application of non-saline shales with clay or sand materials to improve the physical properties of the sandy soils or to increase permeability of heavy clay soils.•Leaching salt using modified surface irrigation.•Cultivate salt tolerant crops.•It recommend no deep plowing because salts are i.