STORING WATER IN THE SOIL 95 
spring when plants are not growing. If the rains 
that fall during the growing season are indispensable 
in crop production, the possible area to be reclaimed 
by dry-farming will be greatly limited. Even when 
much of the total precipitation comes in summer, 
the amount in dry-farm districts is seldom sufficient 
for the proper maturing of crops. In fact, successful 
dry-farming depends chiefly upon the success with 
which the rains that fall during any season of the 
year may be stored and kept in the soil until needed 
by plants in their growth. The fundamental opera- 
tions of dry-farming include a soil treatment which 
enables the largest possible proportion of the annual 
precipitation to be stored in the soil. For this pur- 
pose, the deep, somewhat porous soils, characteristic 
of arid regions, are unusually well adapted. 
Alway’s demonstration 
An important and unique demonstration of the 
possibility of bringing crops to maturity on the 
moisture stored in the soil at the time of planting 
has been made by Alway (Fig. 27). Cylinders of 
galvanized iron, 6 feet long, were filled with soil 
as nearly as possible in its natural position and con- 
dition. Water was added until seepage began, after 
which the excess was allowed to drain away. When 
the seepage had closed, the cylinders were entirely 
closed except at the surface. Sprouted grains of 
