EXPERIMENT
Take a lamp-chimney and fill it with fine, dry dirt. The dirt from a road or a field will do. Tie over the smaller end of the lamp-chimney a piece of cloth or a pocket handkerchief, and place this end in a shallow pan of water. If the soil in the lamp-chimney is clay and well packed, the water will quickly rise to the top.
By filling three or four lamp-chimneys with as many different soils, the pupil will see that the water rises more slowly in some than in others.
Now take the water pan away, and the water in the lamp-chimneys will gradually evaporate. Study for a few days the effect of evaporation on the several soils.
SECTION V. DRAINING THE SOIL
A wise man was once asked, "What is the most valuable improvement ever made in agriculture?" He answered, "Drainage." Often soils unfit for crop-production because they contain too much water are by drainage rendered the most valuable of farming lands.
Drainage benefits land in the following ways:
1. It deepens the subsoil by removing unnecessary water from the spaces between the soil particles. This admits air. Then the oxygen which is in the air, by aiding decay, prepares plant food for vegetation.
2. It makes the surface soil, or topsoil, deeper. It stands to reason that the deeper the soil the more plant food becomes available for plant use.
3. It improves the texture of the soil. Wet soil is sticky. Drainage makes this sticky soil crumble and fall apart.