Methods of Use of Fertilizers 209 



crops which are grown in rotation possess a high fertility 

 value and a low commercial value, and where one crop is 

 regarded as the chief "money-maker." The system de- 

 mands that to this crop shall be applied such an abundance 

 of plant-food as to insure a continuous feeding, and a con- 

 sequent maximum production, even though adverse condi- 

 tions intervene. Thus by a liberal supply of food, a money 

 crop is secured which is as large as climate and seasonal 

 conditions will permit, though which does not require all 

 of the food applied. Hence the residue may be depended 

 upon to fully nourish the remaining crops in the rotation, 

 or at least the immediately succeeding ones, thus saving 

 direct outlay for them. This system may be illustrated 

 as follows : 



On soils in good physical condition, and naturally well 

 adapted for growing potatoes, this crop is selected as the 

 "money-maker" in the rotation, which consists of corn, 

 potatoes, wheat, clover and hay. The potato crop is 

 fertilized so liberally, say with 1500 pounds to the acre, 

 of a fertilizer containing 



Nitrogen 4% 



Phosphoric acid 8% 



Potash 10% 



as to insure its maximum growth under average conditions. 

 The removal of a large crop would still leave a large residue 

 of plant-food, which would provide the following wheat 

 crop with at least all of the mineral elements necessary to 

 produce a maximum crop. If the wheat does not show 

 vigorous growth in the spring, it is lightly top-dressed with 

 nitrate of soda, which not only feeds it directly with 

 nitrogen, but strengthens and invigorates the plant, en- 

 abling it to secure the minerals needed. The removal of a 



