الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
1. Introduction
Soil degradation is a serious problem that concerns more
than 15% of the landmass. Arable lands are the most affected
land by the aspect of soil degradation. El-Husseiny (2011)
reported that; in Egypt, the agricultural area is very limited and it
does not exceed 3% of the total country area. This area is
subjected to reduction due to various natural causes or anthropic
activities. In North-Western Coast region, the most promising
area for agricultural expansion, the cultivated areas is exposed
annually to intensive rainstorms, which affect the main soil
properties and crop productivity.
Rainfall-induced surface sealing which forms as a result
of the impact of the occasional heavy rainfall events on
unprotected soil surface, causes many negative effects on
infiltration, water holding capacity, soil aeration, overland flow,
nutrient losses, and seedling emergence (Assouline, 2004).
Because of these unavoidable damages, surface sealing is a very
serious soil degradation factor which threatens calcareous soils
(Morin, 2003).
Many studies investigated soil surface sealing from
different points of view. However, assessment of sealing impacts
on soil and environment needs further investigations. The current
work aims at evaluating calcareous soils surface sealing and
assessing surface seal impacts soil characteristics and seed
germination.
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