الفهرس 
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Abstract
1-Introduction
Soil is limited resource and could be renewable and cover most lands of the earth, (Blum, 2006). Cultivated land represents about 40 – 50 % of the earth (Scherr, 1999 and Davis and Masten, 2003), 20 of which are severely degraded (Scherr, 1999; Adams and Eswaran, 2000 and Davis and Masten, 2003). According to UNDP (2007), agriculture is the backbone of the economy in many countries, especially the least developing ones. Agriculture is one of the world’s most important activities supporting human life.
Soil fertility is an inherent capacity of it to supply crops grown on it with nutrients in adequate amounts and suitable proportions, whereas soil productivity is a wider term referring to the ability of a soil to yield crops (Dengiz, 2007). Darst and Stewart (2007) reported that, understanding the principles of soil fertility is vital to efficient crop production and environmental protection. Declining soil fertility is closely linked to productivity is one of the root causes of declining per capita food production (Sanchez and Leakey, 1997). Soil fertility decline is an important cause for low productivity soil (Sanchez, 2002). Soil fertility is an important factor in the growth, productivity and quality of plants (Zhang & Xu, 2005). Kafr EL-Sheikh governorate can be considered one of the most important areas in Egypt, which calls “the governorate of the hope and the future” due to its location and wealths. Whereas, this governorate suffers from the most common stresses in Egypt including pollution, salinity, alkalinity and waterlogging. Great problems have been recorded in Kafr EL-Sheikh related to stressed environments and suggested solutions also have been addressed. Therefore, a sustainable management should be adapted for overcoming these stressed environments in Kafr EL-Sheikh. Kafr EL-