150 EG YP TTA N A GE TC UL TIW /;. 



CHAPTER V. 

 IRRIGATION AND DRAINAGE, 



WATER being an absolute necessity of plant life must be 

 supplied, in an almost rainless country like Egypt, by 

 artificial means. It is needed: 1st, directly to increase 

 the growth of the plant of whose weight it forms a large 

 proportion, 2nd, to form a solvent of the otherwise unas- 

 similable plant food in the soil, 3rd, to supply the very large 

 amount of moisture exhaled or transpired by the plant, 

 4th, to fit the soil for those bacterial organisms which 

 exercise so large an influence on plant life. Water does 

 more than meet these physiological demands of the plant, 

 for it also brings a large amount of plant food either in 

 solution, or in suspension in the form of the rich red 

 silt of the Nile in flood (see p. 25). 



There are two systems of irrigation in Egypt, the Basin 

 system of Upper Egypt, and the Canal system of Lower 

 Egypt. 



The basin system seeks to utilize the Mle water only 

 during flood. The whole country is divided into large 

 blocks surrounded by high strong earth banks, often pitched 

 with stone to resist wave action. There were till recently 

 over 200 basins, with a gross area of 1,435,000 feddans, 

 which is an average of 7,000 feddans, but the individual 

 areas vary greatly from some small ones of 700 feddans to 

 the huge Koshesha Basin of 75,400 feddans. When the 

 Nile rises, these basins are filled to a depth of 1 to 2*5 metres 



