BRANDS OF FERTILIZERS 343 



technical knowledge for its efficient conduct. There are 

 many fertilizing materials put up under numerous 

 brands that must be selected from and applied to a great 

 variety of crops grown on innumerable types of soil. 

 The result is that an economical fertilizer practice is 

 difficult to establish, and the use of fertilizers is usually 

 conducted in an entirely empirical manner. 



210. Brands of fertilizers. Each manufacturer or 

 compounder of commercial fertilizers places on the 

 market a number of brands of fertilizers that have some 

 trade name, frequently implying the usefulness of the 

 fertilizer for some particular crop, but without reference 

 to the character of the soil on which it is to be used. 

 Each brand of fertilizer is usually composed of several of 

 the constituents that have been described. If those sub- 

 stances are used that are difficultly soluble, the ferti- 

 lizer is not so valuable as if composed of easily soluble 

 substances. The solubility, as well as the percentage 

 of each ingredient of the fertilizer, should be known by 

 the purchaser. 



A fertilizer is known in the market as a high-grade or 

 a low-grade product, depending upon the percentage of 

 fertilizing constituents that it contains. Low-grade 

 fertilizers are cheaper than high-grade merely because 

 they contain less plant-food, although the price per 

 pound of plant-food may be no less, and, in fact, is 

 usually more. The low-grade product is encumbered 

 with a large amount of inert material, that adds to the 

 cost of transportation and handling, without adding 

 to the value of the fertilizer. For these reasons, the high- 

 grade material is almost always the cheaper fertilizer. 



