THE IRRIGATION AGE. 199 



beyond the break without water. One man can take care of a con- 

 siderable number of these furrows at once, and under favorable 

 conditions of surface and water supply can accomplish the irrigation 

 of as great an area in a given time as by the flooding system. 



This method is also applicable to the irrigation of corn, and in 

 fact of any crop whatever which is planted regularly in rows, a 

 single furrow between each two rows being generally used for such 

 crops. When applicable it is the favorite method, both for its con- 

 venience and the economy of water thereby effected. But where the 

 ground is very irregular this plan is often inconvenient, for the 

 reason that the furrows paralleling the rows of crop would, upon 

 such surfaces, be up and down hill, and would therefore not carry 

 water. To make this method applicable in such cases it would be 

 necessary that the rows follow approximately the contour of the 

 ground, in order that the parallel furrows might carry water through- 

 oat their length. The irrigation of irregular surfaces, however, is 

 generally conducted under the flooding system, except in localities 

 where, as in parts of southern California, the value of the crop 

 frequently warrants the expense of leveling off or terracing irregular 

 surfaces, or the application of water through buried pipes, as it is 

 arranged in the water supply of cities. 



COMPARTMENT SYSTEM. 



A modification of the flooding method is the compartment or 

 check system of irrigation practiced in some localities, particularly in 

 portions of Arizona. This consists in dividing the field to be irri- 

 gated into squares or compartments by levees or dikes of such height 

 as to cause the water to stand over the entire arear of compart- 

 ments at one time, the water being admitted to each compartment by 

 means of a gate in the levee. The water is allowed to stand until the 

 ground has become properly moistened, the time depending largely 

 upon the character of the soil. The compartments or squares vary in 

 size according to the ground, but are not usually more than an acre 

 or so in area. 



