68 EXPERIMENT STATION. [Jan. 



chemical composition of this class of goods, the variation in 

 some cases amounting to 10 or 12 per cent, in some one ele- 

 ment of plant food which is recommended and nsed by dif- 

 ferent manufacturers in compounding a fertilizer for some 

 special crop. This is proof positive that the purchaser of 

 commercial fertilizers must have some more reliable method 

 of selecting his fertilizers than by using the manufacturers' 

 trade names, which, being so contradictory, confuse rather 

 than aid the intelligent buyer. No infallible rule can be 

 laid do^vn in selecting a fertilizer, as so much depends upon 

 the method of crop rotation, the kind of farming in practice, 

 and general soil conditions and requirements. The user of 

 commercial fertilizers will, however, make no mistake in se- 

 lecting a high-grade fertilizer ; but wdiether to select a fer- 

 tilizer containing a high percentage of some one element of 

 plant food, and how to be guided in this matter, must rest 

 with the individual consumer. The plant food requirements 

 of different soils, as well as different crops, vary widely ; and 

 the farmer must discover what particular fertilizing element 

 or elements will most benefit his soil, and select his fertilizer 

 accordingly. 



