Crossville chronicle. [volume] (Crossville, Tenn.) 1894-current, 1917-10-17
PREVENTING EROSION OF FARM LANDS
BY Different METHODS OF TERRACING
Arrangement Disposition Of Soil to Retard Rapid Movement OF
Surface Water-Leve Bench Type Used in Europe, emma
and in Sections of the United States

prepared by the United States Depart
ment of Agricultural
The greatest benefits from the va
rious methods of preventing erosion
come when they are applied in con-
nection with n system of terraces.
AS applied to the protection of farm
lands, terrace is any arrangement or
disposition of the soil the object OF
which is to retard the rapid movement
of surface water and thereby arrest
the process of erosion. According 10
the earliest practice, terracing con-
sists of building land up In series OF
level areas resembling stair steps, the
interval between the rises being nor
izontal and the rise itself being vert-
cal or nearly so. This type of terrace
has long been used extensively In Eu-
rope and China and is used to great
extent on the sleeper lands In the
United States. 1t is known generally
as the level-bench terrace. but to
avoid confusion in the use of the term
level" it will be referred to AS the
horizontal bench terrace. Strictly
speaking, this is the only true terrace,
but the word terrace" In this coun-
try is applied also to ridges OF soil
thrown up and located in such man.
ner as to prevent the rapid flow of
water down slope. This type OF ter
race will be referred to as the ridge
terrace to distinguish it from terraces
of the bench type.
Bench Terrace.
Bench terraces are of two classes
depending upon whether the bench Is
horizontal or sloping. There are not
many good examples of the true horl-
zontal-bench terrace in this country,
while the sloping-bench terrace Is
quite common. This is due to the fact
that the horizontal bench is developed
from the sloping bench by the grad
ual movement of the soil down the
slope. owing to erosion, and TO the
use Of the hillside pillow, which always
throws the soil down the slope. The
time required for the leveling down OF
a sloping bench depends upon the
amount of soil moved down the slope
each year and upon the vertical dis
--rnca- hets eaa the terraces. 1t is nee
asssaffy Is nmainfa&in a -=of earth
at the lower side $of the bench for slop-
ng-bench terraceS and it is advisable
that this be done Nor Northumberland
terraces, for the purpose of retaining
that norton of tile rain water which
does not sink intoi the soil. This Shout
der and the lOweY side Of the embank-
ment should be Seeded to grass. The
sod permits the use of a steep slope
on the lower sidr of the embankment
and protects both the shoulder and
the embankment from erosion due to
surface water (Overtopping the Shout
der. The leveAing-down process men
toned above sometimes is continued
until the slope of the bench is re-
versed. Thus, the water falling on
the bench Will flow to the foot of the
embankment,t above
Fav3r Wide Benches.
In the field studies of the depart
ment, the best terraces were found
where the greatest height and width
of shoulder were used with the small
est vertical distance between the ter
races. 1t is believed that the height OF
shoulder should be not less than 90
foot for Northumberland terraces or
less than foot for newly constructed
sloping-be terraces, and that the
width should be not less than feet for
the former or less than 3 feet for the
latter. The vertical spacing between
the terraces should be governed by
the type of soil, the slope of the land,
and the ease of starting and maintain
Ing a heavy sod on steep and high
embankment. The best practice indi-
Gates that this spacing never should
be. less than feet nor more than q
feet. The smaller spacing should be