198 CALIFORNIA FRUITS: HOW TO GROW THEM 



certain of the heavier soils, particularly, the use of water in many 

 shallow furrows followed by cultivation results in the formation 

 of a compact layer, and this prevents the percolation of the water 

 into the subsoil. This discovery led many Southern growers to 

 resort to fewer and deeper furrows and to new devices to enable 

 the tree to get the benefit of the water. There has been wide 

 use of the subsoil plow, with a wedge-shaped foot attached to a 

 slim standard rising to the ordinary beam. The standard opposes 

 its thin edge to the soil so as to cleave it with the least difficulty, 

 and the foot, passing through or beneath the hardpan, lifts and 

 breaks it. The result of the subsoiling is to open a way for the 

 water to sink and spread below the hardpan. It is usual to run 

 this plow once through the center of the interspace between the 

 rows of trees, sometimes at right angles to the irrigation furrows. 

 When this is done the water is admitted to the furrows as usual, 

 but instead of flowing along smoothly it drops into the track of 

 the subsoiler and runs there a long time before rising again to 

 continue its course down the furrow. It is the experience of some 

 growers that the water has taken five or six days to reach the 

 lower end of the furrows, a distance which would have been 

 covered in twenty-four hours if the subsoiler had not intervened. 

 This has been shown to result in much water for the subsoil and 

 a notable invigoration of trees which had been famishing, although 

 shallow-furrow irrigation had proceeded regularly. 



Recent changes in the furrow method at Riverside, California, 

 are described by Mr. J. H. Reed as follows : 



The handling of the water in the orchard has materially changed in recent 

 years. Instead of flooding up, basining, or using shallow furrows, deep fur- 



Irrigation of fruit trees by large furrows between rows. 



