CULTIVATION 81 



processes by which the soil is disturbed or moved or by 

 which the character of the soil is changed. The term 

 "Tillage" includes all operations by which the soil is dis- 

 turbed or moved. Amelioration includes those processes 

 by which the character is changed by adding or taking 

 something from the soil. Cultivation in the crop will be 

 fully considered under each special crop so that it is un- 

 necessary to enter into any detailed consideration of the 

 subject in this chapter. 



The processes of amelioration deserving special note 

 are Drainage, Washing, Warping and Manuring. Drainage 

 is the means employed to carry away excess of soil water, 

 that is to lower the water table in the soil. Washing (in 

 conjunction with drainage) dissolves and carries away 

 from the soil injurious salts and soluble plant food material. 

 In place of washing, the surface incrustation of salt is 

 sometimes, on a small scale, removed from the land by 

 the kassabieh. Warping consists in running Nile flood 

 water on to land and allowing it to stand until the mud 

 is deposited, when the clear water is run off and the land 

 is again covered with muddy flood water. This can only 

 be carried out Avhere there is an abundant supply of flood 

 water. Warping frees the soil from salts and is an excellent 

 method of improving the quality of sandy soil by the 

 deposit of the rich Nile mud. 



Manures are bodies which contain, relatively to soil, a 

 high amount of plant food in a more or less easily available 

 condition. They are applied to the soil with the object 

 of increasing the amount of food available for the crop. 

 In manuring, that quantity and variety of manure should 



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