168 



CALIFORNIA FRUITS: HOW TO GROW THEM 



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

 some flat lands where winter irrigation is used to supplement rain- 

 fall when the l^ter 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 unacquainted with 

 better methods or who count their trees of too little account to 

 warrant extra effort. It seems, therefore, a fair conclusion 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 methods to a 

 furrow system wherever practicable, because the former requires 

 more soil shifting, a larger head of water for economical 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 

 or basin system prevails, and on fine, retentive loams, the furrow 

 system is without 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 for 

 vineyards and orchards of deciduous fruits. With fruits, however, 

 even in the same district, the tendency is toward using smaller 

 checks carefully leveled before planting. With the large-check 

 system permanent levees, either in rectangular form or on the con- 

 tour plan, are generally used. The small-check system is chiefly laid 

 off with temporary levees, quickly made with special appliances 

 and as quickly worked back to a level as soon as the ground dries 

 sufficiently after irrigation, and the whole surface kept well cultivated 

 until the time arrives for a restoration of the levees for the next 

 irrigation. The latter is the leading horticultural mode. It is care- 

 fully described by Mr. Sydmer Ross, of Fullerton, Orange County, 

 California, as follows : 



The check system, as carried out in the best-handled orchards, entails 

 much hard work, but after you are through with an irrigation you know that 

 each and every tree has had its full supply of water or you know the reason 

 why. The ground must be cultivated, say, about 5 inches deep, so as to have 

 lenty^of loose soil with which to throw up a high ridge. Then a four or six 

 horse ridger" should be run once each way through the rows, if it is a citrus 

 or deciduous orchard, or twice should the trees be walnuts, because these 



