24 



THE OLIVER PLOW BOOK 



Another feature that must be taken into serious con- 

 sideration is that soils, in which water rises rapidly, dry 

 out equally fast, thus the sandy soils dry out much 

 quicker than the clay soils, all of which goes to show that 

 the finer the soil particles are, the stronger the attrac- 

 tion to hold the water. 



Compare the water in the loamy sand and clay tubes illustrated on 

 page twenty-three with those illustrated above. The granular mulch on top 

 the tube of loamy sand stopped the upward trend of moisture as the 

 distance the water in the clay tube has travelled upward shows. The 

 moisture in the loamy sand tube has climbed from a point just below the 

 wire to the granular mulch while the water in the clay tube travelled 

 twice as far as it had, thus showing that the granular mulch stopped the 

 upward trend of moisture. This illustration serves to show the import- 

 ance of keeping the soil particles on the surface in an entirely different 

 arrangement from those below in order that capillary attraction may be 

 permitted to act up to this point and then stopped, thus peeping the 

 moisture in the ground. 



Observe further the soil at the top of the tube filled 

 with loamy sand; that the water has not penetrated the 

 clods to any appreciable extent. Bearing in mind the 

 illustration of the tube with the clods in the center, it 

 will be observed that a granular surface on top is better 

 to prevent moisture from escaping into the air than the 

 finely pulverized soil. The reason for this is simply 

 that capillarity has been broken up between the com- 



