EXPERIMENT STATION BULLETINS. 455 



perfect as it is possihle to make them. "Fertilizers are foods (not stimu- 

 lants) for healthy soils. They are not medicine for sick land." 



Study your soil conditions and by experimenting determine what 

 forms of plant-food, if any, are required and in what amounts they should 

 be used to produce the most economical results. Only in this way can 

 these questions be definitely answered, 



LICENSED BRANDS. 



Thirty-six manufacturers and fertilizer companies have licensed 301 

 distinct brands for sale in the State during the season of 1916. The 

 brands appearing in the following tables of analyses, and none others, 

 can be legally sold. 



Parties mixing or importing fertilizers for their own use and not for 

 sale are not affected by the restrictions of the law and neither are they 

 protected under it. 



COLLECTION OF SAMPLES. 



The collection of samples was made during the spring and fall shipping 

 seasons by inspectors appointed by the State Board of Agriculture. All 

 sections of the State in which fertilizers are used to any extent were 

 covered and 600 samples secured from stocks being offered for sale by 

 dealers. For this purpose a specially constructed tube is used which 

 permits of securing a core from the entire length of the bag. In no 

 case is a sample drawn from less than five bags nor from bags that have 

 previously been opened. The samples are drawn and sealed in the 

 presence of a witness and shipped to the laboratory for analysis. 



As much of the fertilizer used in the State is taken directly from the 

 cars by the consumer, it is never possible for the inspectors to secure 

 samples of all the brands registered. In such cases the samples sub- 

 mitted by the manufacturers at the time of applying for the licenses 

 are analyzed. These samples may be distinguished from the officially 

 collected samples by the omission of the letter "A" preceding the labora- 

 tory number. No analyses are reported for eleven brands as no ship- 

 ments were found by the inspectors and no samples were submitted 

 by the manufacturers. 



RESULTS OP INSPECTION. 



(a) Quantity of plant-food. 



A study of the tables of analyses shows that, of the 549 samples 

 analyzed, representing 290 brands, 92 (16.8%) are below guarantee* in 

 one or more constituent. Thirty (5.5%) are below guarantee in nitro- 

 gen, 38 (6.9%) are below in available phosphoric acid, 6 (1.0%) in total 

 phosphoric acid and 23 (4.2%) in potash. 



* A shortage of more than 0.10 per cent of nitrogen or more than 0.20 per cent available phosphoric 

 acid or potash is considered below guarantee. 



