48 EGYPTIAN AGRICULTURE. 



exceptionable circumstances. The aim in watering should 

 be to apply as light irrigation as possible. Crops generally, 

 and cotton in particular, that have been water-starved 

 must not be watered too heavily when nearing ripeness. 

 Too heavy watering, at a late period of the plant growth, 

 delays ripening and causes the production, of new shoots 

 to the detriment of the resulting crop. Of the many 

 points of importance in the relation of water to the soil 

 the following require to be carefully considered: the 

 water capacity, the shrinkage on drying, the permeability 

 and the movements of the water in the soil. 



The " Water Capacity " of the soil : the capacity of 

 the soil to absorb water when placed in contact with it, 

 and the capacity to retain water after saturation, as after 

 irrigation, are properties of the greatest importance. On 

 the former property depends the power of the soil to 

 draw water from below, and on the latter the power of 

 the soil to retain water against the action of gravity. 

 Both these properties depend chiefly on the texture of 

 the soil. Fine grained soils can absorb and retain most 

 water. When the land is newly flooded the power of 

 retaining water is the more important. When the soil is 

 drying the power of the soil to draw water from below, 

 is of greater importance. This last is more or less a 

 measure of the capillary power of the soil and it is measured, 

 comparatively, by standing the ends of tubes of soil in a 

 basin of water and finding the amount of water absorbed 

 in relation to the weight or volume of soil. The presence 

 of humus and colloid bodies in the soil increases its water 

 capacity. In the same way, as will be pointed out under 



