Tensas gazette. [volume] (St. Joseph, La.) 1886-current, 1917-06-15

prepared by the United States Depart
ment of Agriculture)
The greatest benefits from the va
rious methods of preventing erosion
come when they are applied in con-
nection with 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 to
the earliest practice, terracing con-
sists of building land up in a series of
level areas resembling stair steps, the
interval between the rises being hOr-
izOntal and the rise itself being verti-
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
"levep 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 hori-
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
sloping bench depends upon the
amount of soil moved down the slope
each year and upon the vertical dis
lance between the terraces. 1t is nee
essary to maintain shoulder of earth
at the lower side of the bench for slop-
ing-bench terraces, and it is advisable
that this be done for ACKNOWLEDGMENT
terraces, for the purpose of retaining
that portion of the rain water which
does not sink into the soil. This shout
der and the lower side of the embank-
ment should be seeded to grass. The
sod permits the use of steep slope
on the lower side of the embankment
and protects both the shoulder and
the embankment from erosion due to
surface water overlapping the Shout
der The leveling-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 above. In this case no
shoulder will be required to prevent
the water from washing over and
eroding the embankment.
Favor 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 0.5
foot for bor;zoptol hapcb tarrocac nr
less than l foot for newly constructed
sloping-bench terraces, and that the
width should be not less than 2 feet for
the former or less than 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 heavy sod on steep and high
embankment. The best practice indi-
Gates that this spacing never should
feet. The smaller spacing should be
used on gently sloping land while the
greater spacing applies to steep land.
The question of proper spacing de-
ponds to great extent upon the care
and maintenance of the terraces. I'm
less considerable attention is to be
given to the maintenance of the ter
race banks the smaller spacing should
be used. For the 3-foot spacing a
greater number of terraces are re-
Quired and narrower benches result,
but the terraces are easier to build
and maintain than for greater spac-
ing. However, many farmers favor
the wider benches because of the few
er terraces required and the fact that
Ii is more convenient to cultivate the
field in a few broad strips than in a
greater number of narrow ones. In
other words, they are willing to in
cur a greater loss by erosion for the
sake of greater convenience in cult
walton.
Protection Against Erosion.
When constructed and maintained
properly, bench terraces give excel
Lent protection against erosion. How
ever. many landowners object to this
terrace ON account Of the difficulty of
moving farm machinery from one