THE IRRIGATION OF CITRUS GROVES. 333 



the water from entering. This difficulty Avas overcome 

 by breaking up this hard layer with a subsoil plow and 

 in many cases this method was so vigorously followed 

 that great injury was done the trees. Large numbers 

 of roots were torn up and destroyed. Following this 

 a reaction set in and experience has taught that the 

 best method to pursue in treating irrigation hardpan 

 is to deepen the soil gradually instead of attempting to 

 accomplish it at one operation. The depth of cultivation 

 should be varied from time to time, and the irrigation 

 furrows should open well into the lower soil to permit 

 the free entrance of water. 



In distributing the water through the grove it should 

 be allowed to flow gradually and sink well in. By this 

 plan better results will be obtained with the same amount 

 of water than by applying it in a shorter space of time. 



Following the application of water the soil should 

 be cultivated as soon as its condition will permit. Shal- 

 low cultivation at this time will prevent the formation 

 of a hard crust on the surface and the consequent loss 

 of moisture by capillary movement. 



CHECK SYSTEM. 



Citrus trees may be irrigated by the check method 

 and, when thoroughly done, it leaves little to be desired. 

 It entails a great amount of hard labor in preparing 

 the surface to receive the water, in distributing it and 

 in getting the soil leveled and in tillable condition after 

 the work of irrigation is completed. Generally, the method 

 gives better results on porous soils than the furrow sys- 

 tem. This method is described as follows by Mr. Sy ri- 

 mer Ross, of Fullerton, Cal., in Bulletin No. 108, U. S. 

 D. A., Office of Experiment Stations : 



