The Moisture Of The Soil
Categories:
THE SOIL
Did any one ever explain to you how important water is to the soil, or
tell you why it is so important? Often, as you know, crops entirely fail
because there is not enough water in the soil for the plants to drink.
How necessary is it, then, that the soil be kept in the best possible
condition to catch and hold enough water to carry the plant through dry,
hot spells! Perhaps you are ready to ask, "How does the mouthless plant
drink its stored-up water?"
The plant gets all its water through its roots. You have seen the tiny
threadlike roots of a plant spreading all about in fine soil; they are
down in the ground taking up plant food and water for the stalk and
leaves above. The water, carrying plant food with it, rises in a simple
but peculiar way through the roots and stems.
The plants use the food for building new tissue, that is, for growth.
The water passes out through the leaves into the air. When the summers
are dry and hot and there is but little water in the soil, the leaves
shrink up. This is simply a method they have of keeping the water from
passing too rapidly off into the air. I am sure you have seen the corn
blades all shriveled on very hot days. This shrinkage is nature's way of
diminishing the current of water that is steadily passing through the
plant.
A thrifty farmer will try to keep his soil in such good condition that
it will have a supply of water in it for growing crops when dry and hot
weather comes. He can do this by deep plowing, by subsoiling, by adding
any kind of decaying vegetable matter to the soil, and by growing crops
that can be tilled frequently.
The soil is a great storehouse for moisture. After the clouds have
emptied their waters into this storehouse, the water of the soil comes
to the surface, where it is evaporated into the air. The water comes to
the surface in just the same way that oil rises in a lamp-wick. This
rising of the water is called _capillarity_.