120 BOARD OF AGRICULTURE. [Pub. Doc. 



coming in contact everywhere in the soil with the small root- 

 lets, making it possible to derive a larger proportionate return 

 from the use of a small quantity of fertilizer or than is 

 23ossible to derive from the use of original materials in larger 

 quantities. Farmers should not and seldom nowadays do 

 make the mistake of classing all phosphates in one group. 

 The different products possess different characteristics, dif- 

 ferent chemical qualities, and all have their place in the 

 upbuilding of the farm. 



The recent attempts to encourage the larger use of ground 

 phosphates in place of the bone or of superphosphates is, I 

 am afraid, leading many farmers astray, not because the 

 investigations that have been conducted are not to be de- 

 pended upon ; not because there is not a wide field for the use- 

 fulness of such products, but because of the natural tendency 

 of many farmers to be guided in their purchase by price per 

 ton, rather than by the kind and character of the material 

 contained in the ton. When phosphate rock, containing 26 

 per cent to 28 per cent phosphoric acid, is offered at $8 to 

 $10 per ton, delivered, and acid phosphate, containing 14 per 

 cent " available " phosphoric acid, at $14 to $16 per ton, and 

 ground bone, containing 22 per cent phosphoric acid and 3^/2 

 per cent nitrogen, at $30 to $35 per ton, the farmer who is 

 not well grounded in his knowledge of phosphates and their 

 effect is likely to take "^ a flyer," at any rate on the ground 

 phosphate rock, and the chances are that this kind of a farmer 

 will nine times out of ten never see any eifect from the use of 

 his phosphate rock. It has its place, but it cannot be com- 

 pared with the other two forms or kinds, because it is not com- 

 parable with them in any strict sense, except in the total 

 amount of phosphoric acid carried. The value of a phosphate 

 lies both in its content of phosphoric acid and in the rate at 

 which it will become available. 



Superphosphates and ground bone are suitable for most 

 crops, and returns will be obtained on most soils and on 

 most crops the first year. Ground phosphates are suitable 

 for particular kinds of soil and for particular and special 

 treatment of soils. It is suitable more as an amendment, a 



