VERTICAL FARMING 



63 



and the sub-surface plow. One heavy disc follows behind 

 and bel \v another, and by their cutting, twisting action 

 break and mix the surface soil with a layer of the material 

 lying underneath. Excellent results have been obtained with 

 both forms of deep plows, and their use is strongly recom- 

 mended, as their immediate action is to break up the plow sole 

 hallnwest hardpan material. They also leave the surface 

 and immediate sub-surface in a most desirable condition to 

 receive the rain water and allow it to be conducted to the deeper 

 subsoil that has been shattered with an explosive, where it may 

 be held by capillary absorption. 



Benefit of Using Explosives. It is admitted that present 

 methods of cultivation do not go deep enough, and it must also 

 be admitted that the use of specially prepared agricultural 

 explosives offers the desired remedy. It is admitted by all 



NEARLY IMPERVIOUS CLAY 5UB50IL 



OR 5AA/O 



I'ARATIVK DEPTHS REACHED BY DIFFERENT FORMS OF TILLAGE 



authorities in agriculture that the plow and harrows do not 

 leep enough and they advise the use of subsoilers. Scores 



of books explain how and why each piece of machinery turns 

 r the soil, reduces it to fineness, forms mulches, saves water, 



breaks clods, aerates, stimulates bacteria, etc. If all this wealth 



of invention and labor is worth while bestowing upon the first 

 inches (if the soil why it is not worth following the roots 



