184 



CALIFORNIA FRUITS: HOW TO GROW THEM 



As this writing does not prejtend to be a treatise on irrigation 

 engineering, no attempt will be made to describe the more ambi- 

 tious undertakings, which should never be entered upon without 

 the engagement of a qualified engineer. Nor is it possible to dis- 

 cuss the numerous devices which are covered by patents. Invest- 

 ment should always be preceded by visits to irrigation works now 

 in operation, and procedure should be guided by observation. The 

 hints presented herewith relate chiefly to things the irrigator can 

 do for himself. 



Free Flooding. Flooding that is, the free flow of water over 

 the whole surface, or the flow between rows with furrows near 

 the trees to retain the water in the interspaces is only employed 

 on some flat lands where winter irrigation is used to supplement 

 rainfall when the latter is occasionally below normal. In such 

 cases water is available in large quantities, and the lay of the land 

 favors quite even distribution. Even under these conditions the 

 experience of growers soon leads to the adoption of deep furrows 

 or lateral ditches, or some simple check system, as superior to 

 flooding. Summer flooding is done only by those who are unac- 

 quainted with better methods or who count their trees of too little 

 account to warrant extra effort. It seems, therefore, a fair con- 

 clusion that flooding is only resorted to as a temporary expedient 

 and has little standing. 



The Check System. With soils of such character that vertical 

 percolation is very rapid, flooding in checks, by which water is 

 held upon a particular area until it sinks below the surface, is 

 considered necessary. There is a tendency to change from this 

 method to a furrow system wherever practicable, because the 

 former requires more soil shifting, a larger head of water for eco- 

 nomical operation, more labor to handle it, more working in water 

 and mud, and more difficult cultivation to relevel the land and to 

 reduce a puddled surface to satisfactory tilth. For these and other 

 reasons, perhaps, on loams of medium fineness one may find two 

 adjacent growers pursuing different methods, while on coarse, 

 porous loams the check system prevails, and on fine, retentive loams 

 the furrow system is without a rival. 



The check system can be seen on the most extensive scale in 

 the upper part of the San Joaquin Valley, where the land is so 

 level and water so abundant that the checks can be measured by 

 acres or fractions of acres. In its most perfect form it is found 

 in Orange County and some parts of Los Angeles County, where 

 the checks are measured by feet, rarely by rods. Very large checks 

 are chiefly used for field crops, although also employed for winter 

 irrigation of vineyards and orchards of deciduous fruits. With 

 fruits, however, even in the same district, the tendency is to\vard 

 using smaller checks carefully leveled before planting. With the 



