i8 



When these experiments were planned, the opinion was very 

 generally held that untreated mineral phosphate (apatite) if finely 

 ground became a valuable fertilizer, gradually giving up its phos- 

 phoric acid for the promotion of plant growth. It would appear 

 from many years' experience, that the amount of phosphoric acid 

 that would become available from such an application is extremely 

 small, and therefore, from the practical standpoint, the finely ground 

 Canadian phosphate rock cannot be considered a profitable fertilizer. 



Sulphate of iron, which at the time these tests were begun, was 

 highly recommended as a means of producing increased crops, has 

 also proved to be of very little value for this purpose. 



Common salt, which has long had a reputation for its value as 

 a fertilizer tor barley, with many farmers, while others disbelieved 

 in its efficiency, has been shown to be a valuable agent for producing 

 an increased crop of that grain, while it is of much less value when 

 applied to crops of spring wheat or oats. Some light has also been 

 thrown on the relative usefulness of single and combined fertilizers. 

 Further references to the value and use of clover and yard manure 

 are published in the sections of this bulletin dealing with 'Farm 

 Field Work,' and 'The Work of the Chemical Division.' 



Even a cursory glance through one of the more recent annual 

 reports of the Experimental Farms must convince any one that an 

 almost endless number of experiments and lines of work have been 

 undertaken. In this review it is practicable to refer only to the 

 more outstanding investigations and other works that have been 

 carried on for sufficient length of time to enable more or less reliable 

 conclusions to be drawn. 



