58 CAMPBELL'S SOIL CULTUEE MANUAL 



CHAPTER IX. 



' SUB-SURFACE PACKING. 



By sub-surface packing we mean the packing and 

 firming of the soil at the bottom of the ordinary furrow 

 by a mechanical process and the elimination of the open 

 spaces between large lumps of the earth. 



To those who have been drilled in the theory of sub- 

 soil plowing, and who have been taught that the chief 

 thing is to open up the under soil as much as possible, 

 or those who are not familiar with the great difference 

 there is in soils in different sections of the country, the 

 suggestion of the necessity for firming the sub-surface 

 will come as a shock. 



This sub-surface packing of the soil is something that 

 even the professional students of the subject have found 

 hard to understand. It is something against which 

 some of them have protested, because they have failed 

 to understand all that is involved. But it is a principle 

 which is making its own way. As we will show elsewhere 

 the interest in the subject is increasing at a great rate. 

 Appliances for accomplishing this result are becoming 

 more and more in demand. Practical farmers are learn- 

 ing that it is the thing. 



Sub-surface packing is a purely mechanical process. 

 Special tools are on the market for doing this work, but 

 no matter what tool or implement may be used, the prin- 

 ciple is just the same, and results will follow in proportion 

 to the success which has been attained in doing this nee- 



