vated crops and planted to either trees or sod producing crops
(pastures). The best gully control measure is a preventive
through the use of sod, brush, contour farming and terraces
to either hold or divert the water from the gully channel.
Any kind of aggressive plants, especially those that will bind the
soil such as grasses and vines as well as locust and pine trees,
will control gully formation. In most cases the sod forming
crops are more effective than tree crops within short periods.
(See Plate VIII.)
 Any practice that will break the sod and permit the impact
of rain to agitate the soil, will increase the erosiveness of the
soil and in the long run should be done with care. In other
words, plowing and harrowing prevents the weeds and grass
from covering the land and allows the rain to agitate the soil,
permitting water or wind to carry off the finer particles or cream
of the soil. This is emphasized on land where cultivated crops
are frequently grown compared to grass land. The comparative
losses under different management may be seen in Plate VIII
(Lower right). This graph represents soil losses over a six
year period in Missouri.
 For those crops which require inter-tillage, it is necessary
to construct terraces. (See Plate VI.) This is done with tractors
and terracing machines in all soil conservation regions. In
some cases teams are used to construct terraces. Then to further
control erosion the inter-tilled crops are arranged in a strip
crop fashion with those that do not require tillage. These strips
or non-tilled crops serve to hold any soil material that may wash
from the plowed areas. (See Plate VII.) As a further measure,
crops are rotated in such a way that intensively tilled crops
will not be on the same area every season. In many instances
it is necessary to use commercial fertilizers to stimulate a cover
on eroded soils. This is usually a profitable measure in the long
run.

 It is very desirable to keep all soils covered with plants as
much as it is practical; where land is too steep for cultivated
crops, trees should be planted. Any kind of plant or cover
on the land will materially retard erosion losses as well as leach-