APPENDIX. 109 



force or invite the main roots two or three feet down- 

 wards into the ungenial subsoil. 



Our chief reasons for this shallow planting are these : 

 it is nature's own method of growing trees, and experi- 

 ence has proved to us that man has never devised a 

 better. In the forest and field, wherever trees grow 

 naturally, you will always find the largest number of 

 roots just under the surface of the earth, in the top 

 soil. Few or no roots, except the tap roots, extend 

 downwards very deeply, but in the forest they run 

 along for an immense distance just under the mulching 

 of leaves, which both feed and protect them. A com- 

 mon loamy soil is only about six or eight inches deep, 

 and this is all the material there really is in a field in a 

 condition to furnish food for trees. Now, if you set a 

 tree very near the surface of the ground, the roots will 

 extend rapidly, freely and widely in the good top soil, 

 and there they find their appropriate nutriment. If the 

 light is excluded by mulching, as is done in the forest 

 by leaves, you have all the conditions necessary for 

 chemical changes in the soil, and root feeding, viz : 

 heat, moisture and darkness; and no crude, cold, sour, 

 uncongenial particles of matter to obstruct or poison the 

 roots. Decomposition is constantly going on in the 

 surface soil, and this is materially aided by plant life, 

 which vegetable physiologists tell us acts like a ferment 

 in dough, or like lime in muck, setting up chemical 

 changes in the soil, which go on afterwards to an almost 

 unlimited extent. 



