28 VERTICAL FARMING 



by the too concentrated food, and are left in worse shape than if 

 there had been no fertilization and they had been forced to draw 

 all their food from the soil minerals. 



Even where the conditions are normal rather than extreme, 

 the increased growth caused by the fertilizer calls for a greater 

 supply of moisture to support the enormous loss through evapo- 

 ration from the leaves, and the fertilizer has in no way met 

 the increased demand for the water. The correction for either 

 condition is simply the prevention of excessive amounts of the 

 water being lost by drainage and holding it stored in a deep 

 tilled, open subsoil. A tight subsoil will not absorb and hold 

 the moisture in this way and needs the welcome relief of a 

 small amount of well placed explosive to shatter and open the 

 soil, so that it can meet the demands for more water. 



QUESTIONS 



1. Name in full the conditions necessary for heavy yields of 



your money crop. 



2. What fertilizing material is lacking in your soil, and in what 



form would you supply the deficiency ? 



3. Do the large brace and tap roots of plants absorb plant food 



from the soil ? What is their duty ? 



4. Will a large tree draw most of its food from the ground 



immediately around the stump or from the soil further 

 away? 



5. What is the source of the most used chemical fertilizer in 



your community, and how is it prepared before being 

 offered for sale? 



6. What effect has lime on clover on your farm? On wheat? 



How can you prove your statement ? 



7. Which shows wilt first during a season of slight rainfall, a 



heavy or light crop ? Why ? 



