Evening star., 1943-07-15
Surface of Lund
Changes Constantly
To the Editor Of The star:

1
ditional point of view which has severely
handicapped the people in America, and
everywhere, in their efforts to combat
erosion. Since productive soil is so sig
nif1cant factor in both war and peace,
I believe The Star may be interested
In some of the scientifically determined
facts disproving the notion that land is
eternal.
! Land unfortunately, does not stay put.
1t is continually changing and shifting.
Perhaps, to clarity these remarks, it
should be pointed out that land" re-
| fers not only to masses of solid earth but
| to the thin surface mantle called top soil.
This porous mantle of productive soil is
| in continual flux and Is the result of the
| gradual interaction of many natural
forces, including vegetation, wind, rain
and sun. Fertile top soil Is the most
precious Of natural resources because it
| is the source of our food. Man, far from
exerting only trivial superficial altera-
tions," has upset the original delicate bal
ance between the natural factors Gre
ating soil and has significantly Influenced
its productivity.
At one time, much of the earthss sur
face was covered with fertile top soil.
Today the total productive soil of the
world Is stringently limited. There are
only about four billion acres OF arabic
land to fill the needs of two billion peo-
pie. That is two acres per capita, on the
average, although nutritionists say that
two and a half acres per capita are
necessary to provide even a minimum
adequate diet. Not all Of the four bill
lion acres is good farm land-only about
one-fourth of it constitutes what Amer
lean farmers would consider as really
good, productive soil. 1t should be noted,
moreover, that some nations have less
than an acre of productive land per
capita.
Here in the United States we have had
tragic evidence that soil Is far from be-
Ing permanent resource. We are now
losing soil by erosion at the rate of about
three billion tons year. Centuries are
required by nature TO build topsoil yet
within the past so to 100 years, largely,
we have witnessed widespread damage to
this irreplaceable resource, through the
impact of rain and wind
Fifty million acres Of once -produc-
tive cropland have been ruined for any
further cultivation Another fifty mill
Ian acres of cropland are in a con-
dition almost as bad. One hundred
million acres more have lost from a
quarter TO three-quarters of their life
giving layer of productive topsoil. And
on still another 100000 900 acres of CROP
land erosion is actively under way.
The effects Of soil erosion are widely
felt. The annual cost runs to some
thing over 5000 900, 900. Reduced crop
yields, abandoned homes, migration,
lowered income, increased food hazards,
sedimentation OF reservoirs and many
other destructive consequences follow in
the wake of erosion.
Most Americans remember the Dust
Bowl of the United States In the 3os.
This was a dramatic and tragic evi-
dence Of the transient character of un-
protected soil. Not all of the region
has recovered yet, and it was only be-
cause preventive work was begun
promptly coupled with fortunate
period Of good rainfall, that recovery
has been as rapid and as thorough
as 1t is.
nce-f1ourisning civilizations have
been obliterated, either directly or in
directly, as result of soil removal All
of the worlds deserts were not always
desert areas Nor were all of the pres
ent poor lands always poor.
The devastation wrought by erosion
has left traces all over the globe. Today
the brave people of China find the
hardships of war intensified by the lack
OF fertile land. China's millions are
now crowded because centuries of CROP
ping exhausted the once-productive up
lands, particularly in Northwestern
China. The Yellow River gets its name
from its load Of silt, the yellow soil it
continually carries off from Chinese
farms. Each year 2,5O0,o00 900 tons of
soil material are deposited in the sea
where it is sometimes visible on the
shallow bed of the ocean miles out.
Man-made erosion is serious menace
to the remaining croplands of the world.
Once topsoil is washed away by water
or blown off by wind, the land loses
its fertility and crop yields decline. Re-
search has shown that in the rich corn
belt of the United States, an inch of
soil lost means a drop in corn yield of
about five bushels an acre. Similar
declines in other essential crops occur
In every agricultural area where soil is
eroded. Good farm land may easily
lose from a half-inch to an inch in
years time, and frequent instances
are recorded of the loss of an inch Of
topsoil as the result of single heavy
rain.
The significance of this decline In
fertility is apparent when one considers
the volume of food production that our
limited soil is called upon to supply
not only during the war, but in the
postwar period. A permanent peace is
hardly possible without a permanent
agriculture. The latter certainly re-
quires land that stays put Only
through a sensible system of farming,
based on soil and moisture conserva-
tion, can the land be kept productive
and lasting. Then perhaps humanity.
too, will have stability and placidity"
H. H. BENNETT.
Editors Note.-The Star is glad to
present Mr.. Bennett's discussion of
soil erosion, although the editorial in
question did net deal with this matter
rSG Mai