214 



IRRIGATION PRACTICE 



under the flooding method. It may be well, therefore, to 

 allow the water to overflow occasionally even under the 



furrow method of 



irrigation. The same 

 effect may be ob- 

 tained 

 placing 



in part by 

 the furrows 

 differently from year 

 to year. Meanwhile, 

 the furrow method, 



FIG. 55. Another type of zigzag furrows. ,-, 



with a given quantity 



of water, will yield as heavily as will the flooding method, 

 and may yield more. , 



126. Summary. In brief, there are, in practice, only 

 two great methods of irrigation: (1) flooding by field 

 ditches, and (2) furrowing. The field-ditch method is in 

 reality a furrowing method, in which the water overflows 

 the banks of the fur- 

 rows. On certain soils 

 and under certain 

 conditions the field- 

 ditch method will be 

 found most service- 

 able; on others, the 

 furrowing method. 

 The closed field 

 methods are likely to vanish quite rapidly because of 

 the large expense of installation and the want of elastic- 

 ity in the system. The method of irrigation by furrows 

 will probably triumph as the great method of applying 

 water to soils for the production of crops. At the present 

 time the field-ditch and the furrowing methods are in 

 chief use. 



Fia. 56. Lath-box for distributing water to 

 furrows from head ditch. 



