THE OEAXGE IN CALIFORNIA — CULTIVATION. Ill 



or blasting, the root-s5'stem can be established in good soil 

 below the "hardpan," or when it is so constituted that when 

 kept irrigated the roots will penetrate it. 



An instance of the latter occurred at Riverside, where Mr. 

 Reed planted a few trees on a terrace bordering on an arroyo, 

 and found what was reported as true "hardpan" near the 

 surface. The trees received "an abundance of water over the 

 whole area for a year," and it was then found that the roots 

 had penetrated it to a considerable distance. 



The term " irrigation hardpan" is quite generally used in 

 the orange-growing district to describe the condition of some 

 small areas in orchards where irrigation and subsequent cul- 

 ture have been careless, or where sufficient attention has not 

 been paid to the difi'erence of treatment required by lighter 

 and heavier soils. 



Of course very sandy soils can be handled sooner after irri- 

 gation than can heavier soils, and when a sandy piece of land 

 containing areas of heavy soil is cultivated as soon after 

 irrigation as the sandiest part will permit, trouble may be 

 expected with the so-called " irrigation hardpan," by the 

 puddling of the subsoil, partly directly by the plow, partly by 

 the soaking-in of clay-water. 



It is usual for orchardists to put in a subsoil plow to help 

 in breaking up the heavy spots of what is called "irrigation 

 hardpan." But this difficulty can easily be overcome without 

 using a subsoil plow, as was shown by the experience of 

 Mr. W. J. Cox, of Glendora, Los Angeles CountJ^ who found 

 that " irrigation hardpan" was forming in a part of his orange 

 grove. He irrigated a few trees that were within reach of the 

 domestic water-supply, and followed this up at the proper time 

 with thorough cultivation. After each irrigation he cultivated 

 a little deeper. As a result of deep irrigation and cultivation, 

 the soil took in water as readily as ever and the trees regained 

 their vigorous appearance. He simply used a chisel-tooth 

 cultivator and plenty of water. 



A somewhat different case was that of Mrs. McKenzie, of 

 Riverside, whose orange grove failed to be profitable, though 

 apparently well irrigated. This orchard had been cultivated 

 to the same -depth until a hard, clay "plow-sole" had been 

 formed. The stratum of hard subsoil was several inches thick 

 and contained a number of large surface roots. She wrote to 

 the California Experiment Station, sending samples of soil for 



