Soil Properties as Affected by Different Land Management Practices in the Sohag Region, South Egypt

In Egypt, there is a growing need for information relating to soil condition, its current status, and thenature and direction of change in response to management pressures. This information are required by landmanagers, and regional, state and national agencies to inform modified management and land-use practices andinvestment to maintain and improve the soil resource. The aim of the present investigation was to monitor thechanges of some important soil properties caused by different management practices and using Geochemical Mapsand Box Whisker Graph to demonstrate the results. Four soil types were selected to carry out this study, which arenamely; cultivated floodplain soils, newly reclaimed soil, wastewater disposal soils and uncultivated Wadi disposaldesert soil. The obtained results show that the reclamation practices lead to increase the silt and clay contents in thereclaimed soils specially in the surface layers, but did not change appreciably by the wastewater disposal practice.The CaCO3 content increases away from the Nile stream toward the desert areas on both the eastern and westernsides. The CaCO3 content in the sites subjected to wastewater disposal is negatively affected by such practiceparticularly in the surface layers. The pH values of wastewater disposal soils in El-Dair sites are greatly decreasedby two to three units and consequently can affect the forms and availability of nutrients and biological activity. Thehigh levels of OM were reported in the newly reclaimed sites situated very close to the lands applied for wastewaterdisposal. Levels of OM in the topsoil layers of the wastewater farmlands at El-Dair range between 0.5 and 23.1%,whereas those of the subsoil layers vary between 0.03 and 1.02%. The surface layer of the reclaimed lands haverelatively higher EC values than the surface layers of the cultivated lands have. The cultivated floodplain soils arenon-sodic soils where the ESP values are less than 15. The exchangeable Na+, in median values, of the reclaimedlands is more than those of the cultivated soils by about three times. Moreover, about 47% of the uncultivated Wadidisposal desert soil sites have ESP values of more than 15 and Ca++ is the dominant exchangeable cation. Theexchangeable cations maintain a descending complex as follows: Ca2+> Na+> Mg2+> K+. The application ofwastewater in both sites at El-Kola and El-Dair doesn't induce an increase in the sodicity of soils. The CEC valuesof the flood plain soils vary between 35 and 80 meq/100g and more than ones of the NRL soils which are 11 - 58meq/100g. In the NRL about 53% of the soil samples have CEC values less than 10 meq/100g, whereas in the landsundergo the application of wastewater disposal, The CEC values vary between 8 and 95 meq/100g.