593 



the station (see Experiment Station Eecord, vol. ii, p. 629) ; Tests for 

 Olive Oil Adulteration (part of a paper read before the Olive Growers' 

 Association at San Francisco, July 8, 1891). 



The following- statements are taken from the article regarding the fer- 

 tilizing of olive trees : 



Analysis of the olive tree. 



Ash 



AVator ami organic matter 



Coinpositiun oftheanh 



Potash 



Soda 



I^ime 



Magnesia 



Oxide of iron 



Phosphoric acid 



Sulphuric acid 



Silica 



Chlorine 



Wood. 



Large 

 brant-hes. 



Per cent. 



0.941 



99. 059 



100.000 



19. 1G5 

 2.250 



57. 574 

 3.652 

 3.275 



11.681 

 2.119 

 0. 281 

 Trace. 



Small 

 branches. 



Per cent. 



e.963 



99. 037 



100. 000 



20. 492 

 4.778 



50. 412 

 6.760 

 3.284 



12. 437 

 1.160 

 0.677 

 Trace. 



Leaves. 



Per cent. 



2.506 



97. 494 



100. 000 



50. 260 

 1.614 



46. 155 

 4.424 

 1.414 



10. 470 

 4.754 

 0.649 

 0.260 



Fru:t. 



Per cent. 

 L422 

 98. 578 



100. 000 



60. 744 

 2.225 



16. 282 

 3.770 

 0.096 

 8. 334 

 L104 

 5.670 

 L581 



The experience of many years has proved to the European olive growers that trees 

 growing in calcareous lands are the richest in mineral matter and give oil of the 

 best quality; these olives are always richest in potash. The other ingredients are 

 not considered so important, because the small quantity needed is always found in 

 the soil. It seems also that an excess of lime exi.stiug in the soil facilitates the 

 assimilation of the potash by the plants; therefore we may say that the olive needs 

 a calcareous soil, rich, especially in potash, and also not deficient in phosphoric acid. 

 Besides the ingredients mentioned, it is important to observe that there was a large 

 quantity of nitrogenous matter contained in the fruit, the kernels being richest in 

 this respect. This fact is not only important in regard to the crop, but also to repro- 

 duction by seed. Without a sufficient supply of nitrogen the kernels would not be 

 completely developed, and therefore the few plants that we should obtain from them 

 would not be vigorous, and would not make fine trees, even after being grafted with 

 good varieties. * * * 



From the investigations of Professor Hilgard, we know that nearly all the soOs of 

 California may be considered as abundantly supplied Avith lime; almost the same 

 can be said for the potash, while phosphoric acid is more sparingly represented. 

 Nitrogen is also found in small quantities only, except in some localities where there 

 is a certain amount of nitrate. According to calculations made from my analyses it 

 appears that a large, robust olive tree, well cared for, in a soil suited to its develop- 

 ment, takes away yearly in its growth and crop the following proportions of the 

 principal ingredients. 



Pounds. 



Potash 



Nitrogen 



Phosphoric acid 



1.016 

 2.006 

 0.458 



In brief, it may be said that California soils are naturally very well adapted to 

 olive culture, provided we increase, by the use of manure, their proportion of nitro- 

 gen and phosphoric acid in localities where these ingredients are deficient. * » » 

 19378_No. 9 2 



