The following 

 the approximate 



table compiled from Hopkins' "Soil Fertility," gives 

 maximum amount of plant food removed from the soil: 



TABLE NO. 5 



The above table gives the amount of each of the three essential 

 elements removed from an acre of soil by some of the principal farm 

 crops. 



To return to the soil all of the plant food removed and some addi- 

 tional, the farmer should apply five good loads or tons of manure to 

 each acre. By applying more than five tons, the fertility will be 

 increased proportionately. It will be remembered that a ton of average 

 barnyard manure contains — 



10 pounds of nitrogen 



From 6 to 7 pounds of phosphoric acid 



From 12 to 16 pounds of potash 



Therefore, five tons would contain — 



50 pounds of nitrogen 



30 to 35 pounds of phosphoric acid 



60 pounds of potash 



making a total of 142.5 pounds which is more than any of the crops 

 mentioned in the foregoing table require. While the corn and cotton 

 crops consume more nitrogen than is returned in the manure, the stalks 

 of both plants are usually left on the ground and finally worked into 

 the seed-bed. 



