36 CALIFORNIA FRUITS: HOW TO GROW THEM 



DEFECTIVE SOILS 



Although California soils are predominantly of the depth, light- 

 ness and richness best suited to the growth and bearing of fruit 

 trees and vines, it should always be borne in mind that there are 

 marked exceptions, and failure to observe this fact has resulted in 

 considerable disappointment and loss. There is in California much 

 land which is bad from a horticultural point of view and it is apt 

 to occur even in the vicinity of lands of the highest excellence. It 

 is, therefore, necessary to advise that the closest examination be 

 made before investment be made in the planting of fruits. 



Although there are instances of deficiency in plant food in Cali- 

 fornia soils and considerable areas of land sterile through excess 

 of saline and alkaline salts, these are usually indicated by the local 

 reputation of the tracts, if the newcomer will take pains to make 

 inquiry. It is rather the more obscure, subsoil conditions which, 

 lead to loss or failure, and they may be unknown even to men who 

 have owned or farmed the land for years for ordinary field crops. 

 These defects are, in the main, three : 



Hard-pan. Good loams may be underlaid near the surface by 

 hard-pan or by layers of heavy clay. These prevent root penetra- 

 tion ; they also limit moisture reception to the shallow surface 

 layer, which is apt to become water-logged for lack of drainage 

 during the rainy season or by excessive irrigation, and to quickly 

 lose its moisture by surface evaporation in the dry season, with 

 no compensation from the tight layer below. In such a situation, 

 then, the plant may suffer severely from excess of water at one 

 time of the year and lack of it at another. Such lands may serve 

 well for some of the small fruits, but not for trees or vines. Under 

 certain circumstances the defects of these soils may be corrected, 

 as will be suggested in the chapter on preparing lands for planting. 



Leachy Sub-soils. Good loams are also occasionally underlaid 

 by layers of coarse sand or gravel, through which water flows away 

 beyond the reach of roots which will only make measured progress 

 through such materials. Trees in such situations are apt to come 

 into distress in the dry season and can only be comforted by 

 frequency and volume of irrigation and fertilization, which may 

 be out of proportion to the returns they are able to make. 



Rise of Ground Water. Good fruit lands are also occasionally 

 rendered defective by the rise of the ground water toward the sur- 

 face so that only a shallow layer is left for root extension the evil 

 being aggravated by the fact that a temporary fall of the ground 

 water induces deeper rooting, which a subsequent rise of the water 

 destroys, and decay of the roots ensues. This trouble has occurred 

 over large areas where excessive irrigation, or the course of leaky^ 



