STATE AGRICULTURAL SOCIETY. 



199 



peninsula which separates San Diego Bay from the ocean. It is cov- 

 ered with thick, low brush, of a kind not specified, and has not until 

 lately been brought into cultivation. The surface soil is very finely 

 sandy, of tawny tint, becoming more decidedly yellowish as the 

 depth increases, and fairly yellow and somewhat more coarsely 

 sandy at four feet depth. VVhen wetted it becomes but very slightly 

 coherent, and on drying falls apart by its own weight. The vigorous 

 growth of chaparral upon it, however, suggests that it must have 

 some substance, and this is confirmed by the following analyses of 

 samples representing a tract of about 2,500 acres: 



Soil, 1 Foot. 

 No. 795. 



Subsoil, 4 Feet. 

 No. 7'JO. 



Insoluble residue 



Soluble silioa 



Potash 



Soda 



Lime 



Magnesia 



Br. oxide of manganese ._ 



Peroxide of iron 



Alumina 



Phosphoric acid 



Sulphuric acid 



Organic matter and water. 



Totals 99.91 



90.4621 



2.4.38 J 



.257 



.194 



.370 



.317 



.054 



1.91fi 



2.790 



.061 



.033 



1.173 



92.9 



100.066 



Hygroscopic moisture 



Absorbed at 12° C. 



3.69 



It is needless to say that soils containing from ninety-one to ninety- 

 three per cent of sand cannot contain high percentages of plant food, 

 as compared with loam or clay soils. But the extreme penetrability 

 of such soils by the roots renders what plant food they do contain 

 extremely available, and as a matter of fact, when of considerable 

 depth, such soils are often both productive and durable. 



In the present case the plant food percentages are no smaller than 

 are found in many of the soils of the southeastern States that are 

 profitably cultivated in cotton, although of much less depth. Com- 

 pared with these the supply of potash in the San Diego soil is fair, 

 and the soda representing possibly injurious sea salts, is but sparingly 

 present. The lime supply for so sandy a soil is very large, and speaks 

 of the high availability of the plant food present. The supply of 

 phosphoric acid in the surface soil is large for such a soil, and not 

 deficient even in the sandy subsoil. The whole compares favorably 

 with those soils of the Gulf coast, on -which sea island cotton has been 

 successfully grown for years, and which are equally or evei^ more 

 sandy. It is therefore certain to be found productive. Among fruits, 

 the olive would probably be best adapted to the situation. 



