THE PRINCIPLES OF FERTILIZER PRACTICE 485 



its proper place, is feasible. The purchase of expensive ready- 

 mixed fertilizers may thus be avoided without necessitating 

 home-mixing. 



For vegetable crops, however, especially potatoes, a com- 

 plete fertilizer is generally advisable. Home-mixing is in such 

 cases necessary. Special soils often demand a complete mix- 

 ture. Muck soils generally require both potash and phos- 

 phoric acid, while sandy soils, especially if the organic matter 

 is low, respond to a mixture carrying all three of the fer- 

 tilizer elements. 



As might be expected, this practice of home-mixing has met 

 with much opposition from manufacturers. In general, it is 

 claimed that the factory goods are more finely ground than 

 those mixed by the farmer, and consequently the ready-mixed 

 goods are not only more uniform but also in better physical 

 condition. Also, the manufacturer is able to treat certain 

 materials with acids, and thus increase their availability. 

 While these reasons are more or less valid, good results may 

 be expected from a fertilizer even though it may not be quite 

 uniform, as the soil tends to equalize this deficiency. More- 

 over, by screening and by using a proper filler, a farmer can 

 obtain a physical condition which will in no way interfere 

 with the drilling of the material. While, obviously, one farm- 

 er alone cannot afford to buy small lots direct from the whole- 

 sale dealer because of the high freight charges, this objection 

 is being met by organizations of various kinds whereby the 

 single carriers may be purchased in carload lots and shipped 

 directly to the association. 



It is evident that by purchasing the separate carriers, a 

 farmer is able to obtain pure high-grade material at a reason- 

 able price. Even if the fertilizers are not home-mixed, an 

 educational value enters. The farmer is forced to study the 

 influence of the materials on his crops more closely and is thus 

 placed in a position to make changes that will tend to a higher 

 efficiency of the constituents. The chances are that he will 



