ess, the flow
being stronger toward the more compact and drier parts. If the soil is
left lumpy and cloddy then capillary water cannot rise readily from
below to take the place of that which is lost by evaporation. If,
however, the soil is fine and well pulverized, the water rises freely
and continuously to supply the place of that taken by plant roots or
evaporation from the surface.

TOO MUCH WATER

Some farm lands contain too much water for the growth of farm crops;
for example, bottom lands which are so low that water falling on the
surface cannot run off or soak down into the lower soil. The result is
that the spaces between the soil particles are most of the time filled
with water, and this checks ventilation, which is a necessary factor
in soil fertility. This state of affairs occurs also on sloping
uplands which are kept wet by spring water or by seepage water from
higher lands. Some soils are so close and compact that water falling
on the surface finds great difficulty in percolating through them, and
therefore renders them too wet for profitable cropping during longer
or shorter periods of the year. Nearly all such lands can be improved
by removing the surplus water through drains. (See Chapter XXV.)

Percolation and ventilation of close compact soils can be improved by
mixing lime and organic matter with them.

NOT ENOUGH WATER

In some sections of the country, particularly the arid and semi-arid
sections of the West, the soil does not receive a sufficient supply
of rain water for the production of profitable yearly crops. These
soils are rendered unfertile by the lack of this one all important
factor of fertility. They can be made fertile and productive by
supplying them with sufficient water through irrigation.

The crop-producing power of some lands is lowered even in regions
where the rainfall is sufficient, because these lands are not properly
prepared by tillage and the addition of organic matter to absorb and
hold the water that comes to them, or part of the water may be lost or
wasted by lack of proper after-tillage or after-cultivation. This
state of affairs is of course improved by better preparation to
receive water before planting the crop and better methods of
after-cultivation to save the water for the use of the crop.

LOSS OF SOIL WATER

Aside from what is used by the crops the soil may lose its water in
the following ways:

Rain water which comes to the soil may be lost by r