ASSESSING CROP WATER REQUIREMENTS ON THE BASES OF LAND SUITABILITY OF THE KOM OMBO WESTERN PLAIN SOILS, WESTERN DESERT, EGYPT

The objectives of this work are to assess soil capability and suitability for agricultural use in Kom Ombo western plain located between latitudes 24o30\ and 24o50\ North and longitudes 32o35\ and 32o50\ East, it in corporate an area of 321000 feddans. To achieve this objective Sentinal 2 image, digital elevation model (DEM) and data limited to land surveying were used for delineating the regions main geomorphic units. Six main geomorphic units were recognized as follows, recent alluvial terraces, old alluvial terraces, pediplain, alluvial plain, wadi plain and rock land. Twenty two soil profiles were dug and pedo-morphologically described, six ground water samples were collected from six wells. Hyperthermic and torric are the common temperature and moisture regimes of the investigated area. Typic Haplosalids, Vertic Torrifluvents, Typic Torrifluvents, Vertic Torriorthents and Typic Torriorthents are the dominant sub great group’s soils. The water wells in the studied area have a moderately quality as the salinity is not exceed 3.41 dSm-1 and sodium adsorption ratio was less than 13 all samples. Land capability evaluation of the identified geomorphic units were evaluated to assess the current and potential suitability for giving the maximum output. The current land suitability of studied soils were categorized in four classes S2, S3, N1 and N2 but class S3 and N1 are the most common with an area 54.5%% and 22.7%, respectively. These soils are suffering from some soil properties, i.e soil texture, salinity and alkalinity, soil profile depth and topography as soil limitations with different intensity degree (slight to severe). By executing the suitable soil improvement practices, the potential suitability classes assessed from classes (S1), (S2), (S3) and N2 grades. The severity can be corrected by application of organic and inorganic soil amendments, salt leaching and levelling of undulating surface. Also, soil suitability for specific crops i.e (field crops, vegetables and fruit trees) were presented for soils developed on the identified and geomorphic units in land suitability tables. The crop water requirements for the selective crops were calculated using CROP WAT 8.0 for windows program.