136 CAMPBELL'S SOIL CULTURE MANUAL 



more certain than with the farmer who lives in a region 

 where there must be a good deal of guessing as to the 

 soil, the rain, the sunshine, and the wind. 



The semi-arid section having more sunshine and less 

 rain makes it possible to not only prepare the soil into 

 the most ideal seed and root bed, but it is also possible to 

 keep the soil about the feeding roots constantly supplied 

 with the necessary amount of both air and water. These 

 coupled with heat and light cause nitrification as well as 

 other chemical action through which almost unlimited 

 plant elements are made available, and it is because of 

 these facts and the further fact that such conditions can 

 not be so readily and so continuously sustained in sections 

 of greater rainfall and more cloudy weather, that the 

 semi-arid sections have the advantage of greater average 

 yields at less average cost, when work is scientifically done. 



