230 Fertilizers 



air. Moreover, if properly carried out, it fulfils the idea 

 of successful agriculture; viz., the production of profit- 

 able crops, while at the same time not reducing, but 

 increasing, the potential fertility of the soil. 



The system should be modified if no farm manures are used. 



In this rotation, if no manures are available, as indi- 

 cated, then the amounts and kinds of fertilizers should 

 be somewhat changed. For example, if it was necessary 

 to supply the corn crop with a sufficient abundance of all 

 the elements in artificial forms, then the proportions of 

 nitrogen should be somewhat greater and the total amounts 

 of the constituents applied to the different crops consider- 

 ably increased. For corn, a mixture consisting of 20 

 pounds of nitrogen, 30 of phosphoric acid and 50 of potash 

 should be applied, and if grown upon raw ground rather 

 than upon sod, it would be desirable to still further in- 

 crease the nitrogen. The oats could be fertilized, as 

 before recommended, while the wheat should have an 

 increased supply of both nitrogen and phosphoric acid, 

 double the amounts recommended when used with 

 manure, besides an addition of at least 10 pounds to 

 the acre of potash. The fertilizing of the clover and tim- 

 othy need not be changed. If, in a rotation of this char- 

 acter, barley were substituted for oats, and rye for wheat, 

 the fertilization need not be materially changed, though 

 the rye possesses a slightly greater power of acquiring 

 phosphoric acid than wheat, and the nitrogenous top- 

 dressings may be omitted, unless the crop is grown 

 primarily for straw rather than for grain. The barley 

 is also less able to acquire its phosphoric acid than the 

 oats, and is especially benefited by nitrogen, though care 

 should be exercised to regulate the amounts applied in 



