soil to the surface and therefore check loss of heat by radiation from
the surface.


VALUE OF ORGANIC MATTER

Figure 33 illustrates a simple way to show the value of organic matter
in the soil. The boxes are about twelve inches square and ten inches
deep. They were filled with a clay subsoil taken from the second foot
below the surface of the field. To the second box was added sufficient
commercial fertilizer to supply the plants with all necessary plant
food. To the third box was added some peat or decayed leaves, in
amount about ten per cent. of the clay subsoil. The corn was then
planted and the boxes were all given the same care. The better growth
of the corn in the third box was due to the fact that the organic
matter not only furnished food for the corn but during its decay
prepared mineral plant food that was locked up in the clay, and also
brought about better conditions of air and moisture by improving the
texture of the soil. The plants in the second box had sufficient plant
food, but did not make better growth because poor texture prevented
proper conditions of air and moisture. "And that's another witness"
for organic matter. Decaying organic matter or humus is really the
life of the soil and it is greatly needed in most of the farm soils of
the eastern part of the country. It closes the pores of sandy soils
and opens the clay, thus helping the sand to soak up and hold more
moisture and lessening excessive ventilation, and at the same time
helping the roots to take a firmer hold. It helps the clay to absorb
rain, helps it to pump water faster, helps it to hold water longer in
dry weather, increases ventilation, favors root penetration and
increases heat absorption. We can increase the amount of organic