two similar pieces of ground near
each other and tested them for water April 29th. Immediately after
testing one piece was plowed. Seven days later, May 6th, he tested
them for water again and found that both had lost some water, but that
the piece which was not plowed had lost 9.13 pounds more water per
square foot of surface than the plowed piece. This means that by
plowing one part a week earlier than the other he saved in it water
equal to a rainfall of nearly two inches or at the rate of nearly 200
tons of water per acre.

HOEING, RAKING, HARROWING, AND CULTIVATING

These operations when properly and thoroughly done tend to supplement
the work of the plow in fitting the soil to absorb rain and in making
a mulch to check loss by surface evaporation. The entire surface
should be worked and the soil should be left smooth and not in ridges.
Rolling cutters and spring-toothed harrows are apt to leave ridges and
should have an attachment for smoothing the surface or be followed by
a smoothing harrow. Cultivators used to make mulches to save water
should have many narrow teeth rather than few broad ones. If a large
broad-toothed tool is used to destroy grass and large weeds it should
be followed by a smoother to level the ridges and thus lessen the
evaporating surface. The soil should be cultivated as soon after a
rain as it can be safely worked.

Rolling compacts the soil and starts a quicker capillary movement of
water toward the surface and a consequent loss by evaporation. When
circumstances will permit, the roller should be followed by a light
harrow to restore the mulch.

Ridging the land tends to lessen the amount of moisture in the soil
because it increases the evaporating surface. It should be practiced
only on wet land or in early spring to secure greater heat.

Drains placed in wet land remove free water to a lower depth and
increase the depth of soil occupied by capillary water and therefore
increase the body of soil available to plant roots.

MANURES AND SOIL WATER

Humus, as we learned in Chapter IV, has a very great and therefore
important influence over the water-absorbing and water-holding powers
of soils. Therefore, any of the farm practices that tend to increase
or diminish the amount of humus in the soil are to be seriously
considered because of the effect on the water content of the soil. For
this reason the application of barn manures and green crops turned
under tend to improve the wate