94 CAMPBELL'S SOIL CULTUKE MANUAL 



Much misleading matter has been printed on the sub- 

 ject of soil physics and in discussing available soil fertility. 

 Professor Milton Whitney, chief of the bureau of soils, 

 United States department of Agriculture, says in Bulletin 

 No. 22, issued by the department, "That there is no apparent 

 relation between the chemical composition of the soil as 

 determined by the methods of analysis used, and the 

 yields of crops; but that the chief factor determining the 

 yield is the physical condition of the soil under suitable 

 climatic conditions." 



It is our candid opinion, based on more than twenty 

 years' of observation and experience, that it is to the 

 highest interest to the farmer to give little attention to 

 the chemical properties of his soil until he has learned 

 well and carefully its necessary physical condition in order 

 that he may utilize nature's many elements and forces 

 found in the soil, also in the air, water, heat and light. 



The general properties of the component parts of the 

 average high level prairies of the semi-arid belt are all 

 that could be desired. In the cultivation of these soils 

 every precaution should be taken to prevent at any and 

 all times during the year any loss of moisture by evapora- 

 tion. It is highly important that these soils never be 

 allowed to dry out. Upon this fact depends much. 



Roberts in his book on the " Fertility of the Land," 

 says: "The percolation of rain waters not only conserves 

 the plant food but improves the physical condition of the 

 land. Just as soon as the soil becomes depleted of its 

 moisture it becomes dead or dormant and life ceases." 



TIME TO WORK THE SOIL. 



In order to secure the best possible physical condition, 

 the greatest care should be exercised to do the plowing, 

 packing and cultivating while the soil is moist- When the 



