PHYSICAL AND CLIMATIC SETTING 19 



REGIONAL AGRICULTURE OF CALIFORNIA 



Although general statements based on the climatic 

 satisfaction of the orange will apply to vast areas 

 of California, as indicated, there are some parts in 

 which such generalization is less true and some other 

 sections in which it does not apply at all. It is this 

 departure of the local from the general which gave 

 rise to the claim that California has not one but 

 many climates : in fact, from slight variations in tem- 

 perature, moisture and soil conditions, measured by 

 the particular requirements of different plants, there 

 may be several climates on a single farm of a few 

 hundred acres. Of course, soil suitability, moisture, 

 exposure and the like, must be more or less closely 

 prescribed and provided everywhere. The problem, 

 however, is more complex in California than in most 

 other farming states because a diversified topog- 

 raphy makes more elevations and exposures, each 

 with its own special characters, available for choice; 

 also because crops are widely grown by two great 

 water systems, rainfall and irrigation: and because 

 California undertakes practically all the crops which 

 are grown in the United States and adds to these 

 some for which all the remainder of the country 

 claims no adaptation. Eealization that similar pro- 

 ducing conditions group themselves in all parts of 

 the State, not by degrees of latitude but by similar- 

 ity which runs largely along lines parallel to the 

 coast line and to the trend of mountain ranges, can 

 best be attained by tracing resemblance from the 



