The Principles of Fruit-gromng 



But these figures teach another lesson. Even at their 

 highest point, the roots of Fig. 20 are 8 laches below 

 the surface. They escape the plow. A like remark apphes 

 to the upper tree in Fig. 21. Compare the lower tree 

 in Fig. 21; this tree is the same age as the others, but 

 had always stood in sod. The roots ran 10 feet in one 

 direction and the total spread of the top was 6 feet; but 

 the roots lie just underneath the surface. 

 This land could not be plowed without 

 great injury to the tree. Let us consider 

 the relation of this tree to moisture: the 

 roots are in the driest part of the soil; 

 the grass is pumping out the water and 

 locking it up in its own tissues and 

 sending it into the atmosphere with 

 great rapidity; the soil is baked, and 

 pulls up the water by capillary attrac- 



FiG. 20. The long roots of a pear tree in very hard land, extending 21 feet and 

 lying 2 J^ feet below the surface at the extremity. 



tion and discharges it into the air; there is no tillage to 

 stop this waste by spreading a mulch of loose and dry soil 

 over the earth. If one were to sink a well under this tree 

 and were to erect a windmill and pump, he could not so 

 completely deprive the tree of moisture; and the less 

 moisture, the less food. 



In comparing apple trees in sod and in tillage at the 

 close of a five-year period, Hedrick found a similar 

 condition: "The roots of the trees in the sod-mulch plat 

 came to the very surface of the ground. How much these 



