Agriculture 323 



cal elements that enter into the tissues of plants and compose 

 the bodies of all animals. The conditions under which the soils 

 have been formed from the rocks, the slow breaking up of the 

 rocks with little rainfall (arid desert conditions) have left the 

 soluble mineral elements of the rocks in the soils. In regions 

 of greater rainfall the soluble mineral elements are leached out 

 and carried away in solution. Hence the richness of desert 

 soils. 



The explanation of the great agricultural empire of the 

 Great Valley of California is a chapter in geologic history. 

 Geologic formations miles in thickness that once lay where the 

 Sierra Nevada mountains are now, have been weathered and 

 eroded and the broken rock carried by streams and deposited in 

 a sea which covered what is now the plain of the Great Valley. 

 These sediments form one of the world's great producing 

 valleys. 



Greatest Variety of Products Known 

 to Ancient or Modern Times 



A greater variety of fruits, flowers, trees, shrubs, grains, 

 grasses, vegetables, cotton, and forage feed crops, is not known 

 to any land. About every known edible fruit and vegetable, 

 except papayas and bananas, are grown in this western sunset 

 land and not only grown but produced in quantities so great 

 that they are shipped to the remote corners of the earth. 

 Flowers no one really knows flowers till he has seen the deserts 

 of California in bloom. The geologically formed mountains 

 which keep off the winds and rain, but which deliver moisture 

 from their crests and down their slopes, have yielded the min- 

 eral elements of the highly fertile soil which by the alchemy 

 of blazing sun in turn results in the brightest and most splendid 

 galaxy of colors known to the traveler's eye. Yes, the geology 

 of soils is the magic key. The weathering processes that have 

 been going on during the ages, while the mountains were being 

 uplifted and the crust of the earth rent and fractured by faults, 



