190G.] PUBLIC DOCUMENT— No. 83. 53 



Table A, on the following page, gives the average com- 

 position of licensed fertilizers for 1905 ; Table B gives a 

 compilation of analyses showing the average percentages, as 

 well as the maximum and minimum percentages, of the 

 three essential elements of plant food found in the so-called 

 special crop fertilizers put out by the different manufac- 

 turers. This latter table shows how unsafe it is to be ffuided 

 wholly by trade name when selecting a fertilizer for any 

 special crop. Out of the several hundred fertilizers that are 

 annually offered for sale in the general markets in Massa- 

 chusetts, it becomes no easy matter for the farmer to select 

 to meet his requirements in cases of the ready factory-mixed 

 goods. No infallible rule can be laid down, as soil condi- 

 tions vary so widely, and so much depends upon crop rota- 

 tion. It is safe to say, however, that the higher-grade 

 fertilizers are the most economical ones to buy. Those fer- 

 tilizers should be purchased which furnish the most nitrogen, 

 potash and })hosphoric acid in a suitable and available form 

 for the same money. 



