The Cook County news-herald. [volume] (Grand Marais, Cook County, Minn.) 1909-current, 1917-06-06
FERTILE LAND RUINED BY EROSION.

FERTILE LAND r
prepared by the United States Depart
ment Of Agriculture)
The greatest benefits from the va
rious methods of preventing erosion
come wien they are applied in con-
nection with a 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 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 a great
extent on the sleeper lands in the
United States. It is known generally
as the level-bench terrace, but to
avoid confusion in the use Of the term
'1evel 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-
zoDtal-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
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 Northumberland
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 embanlkment
| 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 Of
foot for Northumberland terraces O,
less than / foot for newly constructed
sloping-bench terraces, and that the
width should be not less than 2 feet TO,
the former or less than 3 feet for the
latter. The vertical spacing between
the terraces should be governed b,
the type of soil, the slope of the land
and the ease of starting and maintain
ing heavy sod on steep and higl
embankment. The best practice indi
Gates that this spacing never SHOULD
be less than 8 feet nor more than
feet. The smaller spacing should b.
used on gently sloping land while tn,
greater spacing applies to steep land
The question Of proper spacing de
ponds to a great extent upon the car
and maintenance of the terraces. On
Jess considerable attention is to b.
given to the maintenance of the ter
race banks the smaller spacing shoul,
be used. For the 3-foot spacing :
greater number of terraces are re
CURED and narrower benches result
but the terraces are easier to butlt
and maintain than for greater spac
| inR Hnpnver5 anandr farmoxss yfavn,