50 STATE POMOLOGICA.L SOCIETY. 



The orchardist like the general farmer should make a study of 

 the needs of his soil by the means of carefully conducted fertilizer 

 experiments similar to those undertaken by the Experiment Station, 

 the results of which have been given to the public from time to time, 

 and after finding out what his soil needs in the way of fertilizing 

 materials plan his system of manuring accordingh\ 



The sources of phosphoric acid in forms suitable for application 

 are bone meal and ground bone, Thomas-Slag, bone ash, fine 

 ground rock phosphates, fine ground phosphatic guanos and acid 

 phosphates. All of these materials except the acid phosphates 

 should be thoroughly incorporated with the soil either by plowing 

 and harrowing or by pasturing the orchard with swine. 



Acid phosphates may be used as top dressing. The acid phos- 

 phates or super-phosphates are quickest in their action, after which 

 would follow the various bone phosphates, Thomas-Slag and some 

 phosphatic guanos while such material as South Carolina rock are 

 slower to yield their phosphoric acid to growing crops. It is of great 

 importance that all raw phosphates {i. e. those which have not been 

 treated with acid) be finely ground. Bone meal and ground bone 

 usually contain in addition to seventeen per cent or eighteen per 

 cent of phosphoric acid about three per cent of nitrogen. 



The chief source of potash in commercial fertilizers are the Ger- 

 man potash salts from the mines of Strassfurt and Leopoldshall. 

 These salts are put upon the market as muriate of potash, which 

 contain an equivalent of fifty percent — fifty-three per cent of potash. 

 High grade sulphates of potash and magnesia containing thirty- 

 five per cent — fifty-two per cent of potash. Kainit containing 

 eleven per cent — thirteen per cent of potash and a double sulphate 

 of potash and magnesia containing twenty-five per cent — twenty- 

 eight per cent of potash. The cheapest and perhaps the most 

 reliable source of potash of these salts is the muriate of potash. 

 The average cost of potash in the muriate as reported by the New 

 Jersey station for the year 1886 was four cents per pound, while in 

 the other forms it ranges from 4.2 cents to 6.5 cents per pound. 



Another source of potash is wood ashes in which it is always 

 accompanied by phosphoric acid and lime. Wood ashes is a valuable 

 manure on most soils and for most any crop and has been found 

 particularly valuable for orchards. They are quite variable in com- 

 position. The total potash varying 1.53 per cent in a sample of 

 unleached ashes from pine wood from saw mill waste to 12.04 per 

 cent in the ashes from birch wood from a spool factory waste. 



