Sustainable Soil Management to Mitigate Soil Erosion Hazards in Egypt

Abstract

Egypt is divided into three rainfall belts some regions are subjected to both soil erosion types and others are subjected to only wind erosion. The hazards of soil erosion take a variety of forms. In the Northwestern Coast Region (NWCR), few effective events are characterized by high rainfall intensity causing excessive runoff and soil loss. The annual runoff and soil loss were related to the number of them. Runoff also occurred when individual rainfall storm exceeds 10 mm/h. There are different indicators for rainfall erosivity differed in their significance. Concerning soil erodibility indicator for water erosion, there are different classes for it depend on the region. The power function is the best fitted relationship between soil erodibility indicator and estimated soil loss by USLE model. In NWCR, measured soil loss varied according to slope percent and increased with increasing the slope steepness, at the same rainfall erosivity. The enrichment ratios for some nutrients and clay fraction and organic matter were greater than 1. USLE model is the best for the assessment of annual soil loss and used as indicator of soil erosion by water under NWCR. Both climatic factor and soil erodibility indicated that about 80% of the studied areas suffer from wind erosion. Estimated soil loss characterized to three classes low, moderate and severe. These variations are dependent upon the land use. RWEQ could be used to estimate wind erosion rate under NWCZ conditions. Laboratory studies using Rainfall simulator and wind tunnel were used to study some parameters such as slope percent and threshold wind velocity affecting on water and wind erosion respectively. The strategies for soil erosion control mainly depend on different applications which consider some of the principles of sustainable soil management. Such as tillage to a depth of 30 cm with broadcast planting and perpendicular tillage across the slope was efficient for reducing the amount of soil loss. Combined application of organic matter with perpendicular tillage increased the reduction rate of soil loss by different percentage according to rate of organic manure. In addition, using contour tillage for consolidated soil reduced soil loss as a result of water erosion by 73.7, and 51.7%, as compared to the bare soil, and tillage of consolidated soil in up and down slopes, and consequently reduces its carrying capacity. The combination of two or three management measures for controlling soil erosion decreased the magnitude of soil loss likewise the yield of crops increased. From the economical point of view these measures could be used.