The Mulch

Categories: CONTROL OF SOIL MOISTURE

In conserving the supply of water in the soil the mulch

plays an important work. The dry air is constantly taking up the water

from the surface of land, and when the surface is drier than the soil

below, the moisture moves upward if there is no break in the structure

of the surface soil. The mulch is a covering of material that does not

readily permit the escape of water.



The only available material for a mulch in most instances is the soil

itself. Experience has taught that when the top layer of soil, to a

depth of two or three inches, is made fine and loose, the water beneath

it cannot escape readily. It is partly for this reason that the

smoothing-harrow should follow the roller after land has been plowed.

The plow is used to break up the soil into crumbs that will permit air

to enter. The loosening is excessive when the planting must follow

soon, permitting rapid escape of water. The roller or plank-drag is

employed to compress the soil, and to crush crumbs of soil that are too

large for good soil conditions. The harrow follows to make a mulch of

fine, loose soil at the surface to assist in prevention of evaporation.



A sandy soil will retain its mulch in effective condition for a longer

time than a fine clay, if no rain falls. When the air is laden with

moisture, clay particles absorb enough water to pack together and form

an avenue for the rise of water to the surface, where the dry air has

access to it.