94 



SOILS 



and secures a freer movement of soil water from the lower 

 regions to the surface layer above. 



The assistance rendered chemical changes. The ways 

 through which tillage increases the amount of available 

 plant food elements are : 



1. The effect on place and movement of soil particles. 



2. The entrance of the silent soil makers air, water, 

 etc. 



EFFECT OF PLOWING WET LAND 



This is ordinarily an easily cultivated field. It is now ruined for some time 



to come 



3. The mixing of humus and other soil components. 



4. The freer movement of salts and gases. 



5. The influence of tillage on microscopic life. 

 When soil particles are moved from the place they have 



occupied for some time, and brought into contact with 



