cern regards drainage. If the
water from rains is held in the surface by an impervious stratum
beneath, it is idle to spend money in other amendments until the
difficulty respecting drainage has been overcome. A water-logged soil
is helpless. It cannot provide available plant-food, air, and warmth to
plants. Under-drainage is urgently demanded when the level of dead
water in the soil is near the surface. The area needing drainage is
larger than most land-owners believe, and it increases as soils become
older. On the other hand, the requirements of lime, organic matter, and
available plant-food are so nearly universal, in the case of
unproductive land in the eastern half of the United States, that they
are here given prior consideration, and drainage is discussed in
another place when methods of controlling soil moisture are described.
The production of organic matter is so important to depleted soils, and
is so dependent upon the absence of soil acidity, that the right use of
lime on land claims our first interest.

Soil Acidity.--Lime performs various offices in the soil, but farmers
should be concerned chiefly about only one, and that is the destruction
of acids and poisons that make the soil unfriendly to most forms of
plant life, including the clovers, alfalfa, and other legumes. Lime was
put into all soils by nature. Large areas were originally very rich in
lime, while other areas of the eastern half of the United States never
were well supplied. Within the last ten years it has been definitely
determined that a large part of this vast territory has an actual lime
deficiency, as measured by its inability to remain alkaline or "sweet."
Many of the noted limestone valleys show marked soil acidity. There has
been exhaustion of the lime that was in a state available for union
with the acids that constantly form in various ways. The area of soil
thus deficient grows greater year by year, and it can be only a matter
of time when nearly all of the eastern half of this country will have
production limited by this deficiency unless applications of lime in
some form are made. When owners of soil that remains rich in lime do
not accept this statement, no harm results, as their land does not need
lime. On the other hand are tens of thousands of land-owners who do not
recognize the need of lime that now exists in their soils, and suffer a
loss of income which they would attribute to other causes.

Irrational Use of Lime.--Some