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
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.
4. It prevents washing.
5. It increases the porosity of soils and permits roots to go deeper into the soil for
food and moisture.
6. It increases the warmth of the soil.
7. It permits earlier working in spring and after
Fig. 9. Laying a Tile Drain
8. It favors the growth of germs which change the unavailable nitrogen of the soil
into nitrates; that is, into the form of nitrogen most useful to plants.
9. It enables plants to resist drought better because the roots go into the ground
deeper early in the season.
A soil that is hard and wet will not grow good crops. The nitrogen-gathering crops
will store the greatest quantity of nitrogen in the soil when the soil is open to the free circulation of the air. These valuable crops cannot do this when the soil is wet and
Sandy soils with sandy subsoils do not often need drainage; such soils are naturally
drained. With clay soils it is different. It is very important to remove the stagnant water in them and to
let the air in.
When land has been properly drained the other steps in improvement are easily taken.
After soil has been dried and mellowed by proper drainage, then commercial fertilizers, barnyard manure,
cowpeas, and clover can most readily do their great work of improving the texture of the soil and of making
it fitter for plant growth.
Fig. 10. A Tile in Position
Tile Drains. Tile drains are the best and cheapest that can
be used. It would not be too strong to say that draining by tiles is the most perfect drainage. Thousands of
practical tests in this country have proved the superiority of tile draining for the following
1. Good tile drains properly laid last for years and do not fill up.
2. They furnish the cheapest possible means of removing too much water from the
3. They are out of reach of all cultivating tools.
4. Surface water in filtering through the tiles leaves its nutritious elements for
To show the Effect of Drainage. Take two tomato cans and
fill both with the same kind of soil. Punch several holes in the bottom of one to drain the soil above and to
admit air circulation. Leave the other unpunctured. Plant seeds of any kind in both cans and keep in a warm
place. Add every third day equal quantities of water. Let seeds grow in both cans and observe the difference in
growth for two or three weeks.
To show the Effect of Air in Soils. Take two tomato cans;
fill one with soil that is loose and warm, and the other with wet clay or muck from a swampy field. Plant a few
seeds of the same kind in each and observe how much better the dry, warm, open soil is for growing farm