PEDOCHEMICAL STUDIES ON DESERTIC SOILS OF EL SADAT CITY AND NOUBARIA USING SPECTRAL REFLECTANCE.

The current investigation aims to study the geomorphological and pedochemical characteristics of El Noubaria and El-Sadat city soils using the spectral reflectance and GIS technology. Soil classification and land evaluation are also carried out. Moreover, an electromagnetic induction instrument (Profiler EMI-400) was used to assessing soil salinity in the field for selected parts in these areas. Three main geomorphic units were identified in El-Sadat area namely, Flood Plain (3,02% from this area), Alluvial Plain (32,25%), and Aeolian Plain (58,13%). Also, three main geomorphic units were identified in El Noubaria studied area namely, Alluvial Plain (2,78% from this area), Elongated Hills (32,79%), and Calcareous Valley (58,7%). Fifty-five profiles were selected representing the soils of El Sadat units and sixty-four profiles were selected to represent the soils of El Noubaria units. Land and site features are observed and registered. Soil profiles were dug deep down to 150 cm, morphologically described, and samples were collected representing the subsequent layers in each profile for integrated physiochemical analyses. Moreover, the EMI-400 instrument was used for assessing soil salinity in the field for three selected parts in the two studied areas. Soils of the two studied areas are deep having almost flat to gently undulating topography and well drainage system. The soils of El-Sadat area have mostly loamy sand texture while, the soils of El Noubaria have loamy texture. All studied soils are slightly to moderately alkaline, non-to slightly saline especially in some parts of El Noubairia having low Organic matter (OM) and gypsum contents. The soils of El-Sadat area are slightly calcareous, whereas, that of El Noubaria area are strongly calcareous. Most of El-Sadat soils are classified as Typic Torripsaments and some as Typic Torriorthents. While, most of El Noubaria soils are classified as Typic Haplocalcids. According to the land suitability evaluation, most of studied soils are categorized into grade S1. The other soil categories could be maintained by reclaiming their limitations. The statistical analyses indicated that, there was a high significant correlation coefficient between EMI-400 readings and lab determined EC (dSm-1) for measuring soil salinity in the two upper layers in all studied soils especially at band of 15 KHz. The integration between RS and GIS technology was used to produce results and all geomorphic, suitability and salt distribution maps in this work.