HOW TO USE BONES FOR FRUIT TREES 143 



FIRST AID TO THE INJURED SOIL 



Based upon the clear characteristics of California soils as already 

 indicated in the chapter on that subject, Dr. Hilgard advises that any 

 large-scale fertilization should begin with phosphates and nitrogen, 

 and, should this not prove fully satisfactory, then with potash also, this 

 being the order in which these substances are likely to become deficient 

 in most of our soils under cultivation. In the course of time potash 

 fertilization will become widely necessary in this State; in fact some 

 California soils are naturally deficient in potash. 



AVAILABLE SUPPLIES OF PHOSPHATES 



Phosphatic manures which are clearly promotive of freer fruiting 

 of trees and vines, are now being supplied to fruit growers by 

 importers and manufacturers located in various California cities, and 

 results attained by their use are such as to warrant continuance. They 

 are bone and rock phosphates, which are transformed into superphos- 

 phates, and with nitrogenous matter added, serve as good applications 

 both for growth and fruiting. 



Home-Made Bone Manures. Much good bone manure can be 

 made by collecting bones, heads, horns, feet, etc., from butchers' shops 

 or elsewhere. How to make such material available, by simple proceed- 

 ings, is described by Prof. Hilgard as follows : 



1. Bones put into a well-kept (moistened) manure pile will themselves grad- 

 ually decay and disappear, enriching the manure to that extent. 



2. Raw bones may be bodily buried in the soil around the trees; if placed 

 at a sufficient depth, beyond the reach of the summer's heat and drouth and 

 cultivating tools, the rootlets will cluster around each piece, and, in course of a 

 few years, consume it entirely. 



3. Bones may be packed in moist wood ashes, best mixed with a little quick- 

 lime, the mass kept moist but never dripping. In a few months the hardest bones 

 will be reduced to a fine mush, which is as effectual as super-phosphate. Con- 

 centrated lye and soil may be used instead of ashes. In this process the nitrogen 

 of the bones is lost, going off in the form of ammonia, the odor of which is 

 very perceptible in the tank used. 



For neither of these processes should the bones be burned. The burning of 

 bones, is an unqualified destriment to their effectiveness, which can only be undone 

 bv the use of sulphuric acid. 



4. Bones steamed for three or four hours in a boiler under a pressure of 

 thirty-five to fifty pounds, can, after drying, be readily crushed in an ordinary 

 barley-crushing mill, and thus be rendered more convenient for use. Practically, 

 very little of the nitrogen (glue) of the bones need be thus lost. 



POTASH 



Though, as already stated, potash is commonly in good supply 

 in California soils, it is very clear from experience that additions of 

 potash, perhaps in more available form, are advisable. The fruit 

 analyses already given show that the use of this substance by fruit 

 trees and vines is very large. Recent experiments seem to indicate 

 that potash ministers directly to the quality of the fruit in some cases. 



