The Composition and Use of Fertilizers. 247 



PAET III. 

 THE PURCHASE AND USE OF FERTILIZERS. 



One of the questions most commonly asked by farmers seeking 

 information is, " What fertilizer will give me the best results for 

 this or that crop? " It is, of course, impossible to give any 

 definite answer to such a general question involving, as it docs, 

 so many different conditions, none of which is clearly known. 

 The composition and physical properties of the soil, the extent 

 and manner in which it has been previously cropped and fertil- 

 ized, the kind of crop one wishes to grow — all these conditions 

 need to be known and, even then, it will require some special 

 experimenting on the part of the farmer to determine what 

 forms and amounts of fertilizers he can use most economically. 

 The common method employed by farmers in selecting fertilizers 

 is to take some brand of complete fertilizer that has been recom- 

 mended to him by some neighbor or dealer. He has no clear 

 ideas regarding the condition of his soil, and the needs of differ 

 ent crops. He thinks that he must have more fertilizer in order 

 to secure better crops and he buys blindly. Under such cir- 

 cumstances, it is safest, as a rule, for a farmer to select a com- 

 plete fertilizer. However, in so doing, he may be throwing 

 money away by purchasing what his soil and crop may not need, 

 for only one or two of the three chief fertilizing constituents 

 (nitrogen, potash and phosphoric acid) may be needed; and, in- 

 deed, it may be that some physical condition of the soil is wrong 

 and that plant food of any kind is not really needed at all. 



In selecting fertilizers for use, we need to consider several 

 important questions, such as the following: 



1. Under what circumstances a fertilizer should be used. 



2. What constituents of plant food are needed. 



3. What amount of each fertilizing constituent is needed. 



4. In what forms it is best to buy such plant food as is needed. 



5. Which is more advantageous, to purchase complete fertil- 

 izers or to purchase separate ingredients? 



6. To what extent home-mixing is practicable. 



7. Special suggestions in connection with the purchase of sepa- 

 rate ingredients. 



8. Methods and seasons of applying fertilizers. 



