92 DRY-FARMING 
Now, it is to be observed that, generally, plants 
grown in dry climates send their roots straight down 
into the soil; whereas in humid climates, where the 
topsoil is quite moist and the subsoil is hard, roots 
branch out laterally and fill the upper foot or two 
of the soil. This difference is made clear by the 
illustrations herewith produced (Fig. 26). A great 
deal has been said and written about the danger of 
deep cultivation, because it tends to injure the roots 
that feed near the surface. However true this may 
be in humid countries, it is not vital in the districts 
primarily interested in dry-farming; and it is doubt- 
ful if the objection is as valid in humid countries as 
is often declared. True, deep cultivation, especially 
when performed near the plant or tree, destroys 
the surface-feeding roots, but this only tends to com- 
pel the deeper lying roots to make better use of the 
subsoil. 
When, as in arid regions, the subsoil is fertile and 
furnishes a sufficient amount of water, destroying 
the surface roots is no handicap whatever. On the 
contrary, in times of drouth, the deep-lying roots 
feed and drink at their leisure far from the hot sun 
or withering winds, and the plants survive and arrive 
at rich maturity, while the plants with shallow roots 
wither and die or are so seriously injured as to pro- 
duce an inferior crop. Therefore, in the system of 
dry-farming as developed in this volume, it must be 
understood that so far as the farmer has power, 
