PROFITABLE FARMING. 29 



quality of the plant food which it contains. Low- 

 grade fertilisers are often made from inferior 

 materials, whereas high-grade fertilisers must be 

 prepared from the very best class of materials. 



It is very poor judgment to buy a fertiliser 

 because it costs comparatively little per ton 

 unless it contains a fair value of plant foods. To 

 estimate this is unfortunately not generally so 

 well understood as it should be. The manner in 

 which an analysis is stated is apt to mystify, 

 because it is customary to describe a fertiliser 

 as containing so much per cent, or units of 

 soluble phosphate, nitrogen, and so forth, but 

 it is often not understood by the farmer that 

 this simply means pounds per hundred. 



For example, compare a ton of low-grade 

 fertiliser which is offered for, say, 3 los. od. per 

 ton delivered, and analyses 1.25 per cent, 

 nitrogen and 8 per cent, total phosphate, with 

 one ton of high-grade fertiliser offered for say /6 

 per ton analysing 2.50 per cent, nitrogen, 16 

 per cent, soluble phosphate, 3 per cent, undis- 

 solved bone phosphate and 3 per cent, of potash. 

 It will be seen that the latter contains twice as 

 much nitrogen, nearly two and a half times as 

 much phosphates, and in more soluble form as 

 does the low-grade fertiliser, and potash in ad- 

 dition, making a complete fertiliser. Nevertheless 

 the farmer who buys on the ton basis or is guided 

 only by the price per ton will be induced to 

 purchase the low-grade because he apparently 

 saves 2 los. od. per ton. The farmer, however, 

 who studies the relation of pounds of plant food 



