l68 MAINE AGRICULTURAL EXPERIMENT STATION. I9O2. 



COMPARISON OF GUARANTEES AND STATION 

 SAMPLES FOR THREE YEARS. 



It is important for the purchaser of fertilizers to know how 

 the goods have compared with the guarantee, not merely for one 

 year but for several years. Formerly we have printed a table 

 comparing the analysis of the manufacturers' and Station 

 samples for the year with the guarantee. In the table on pages 

 .170 to 175 there is given a comparison of the analyses of the sam- 

 ples collected by the Station for the years 1900, 1901 and 1902 

 with the guarantee of the manufacturers. When the guarantee 

 has been changed in 1900 from that*)f the previous years the fact 

 is indicated by a f, and where more than one analysis of the 

 same brand was made in 1900, this is indicated by a *. 



One of the claims which fertilizer manufacturers are making 

 for the superiority of their goods over "home mixed fertilizers" 

 is that the former are '"manufactured." This should mean, if 

 it means anything, that the goods are more evenly mixed and 

 therefore more uniform. In some instances in which two or 

 more samples of the same brand have been taken and analyzed, 

 they have been found to differ from each other quite materially. 

 The samples were taken with a great deal of care by experienced 

 men from a large number of packages. It would not seem diffi- 

 cult to make "home mixed fertilizers" which should run as uni- 

 form as some of the brands here reported upon. 



In studying the table of comparison of guarantees of the 

 Station samples for three years, it will be found that many goods 

 run quite uniform year after year. This is particularly true as 

 regards phosphoric acid and is readily understood when it is 

 remembered that the "superphosphate" is the starting point and 

 that the materials furnishing the nitrogen and potash are added 

 to this. The potash arid nitrogen are the more expensive sub- 

 stances in fertilizers and greater variations in composition are 

 found in these constituents. 



