The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1902-09-20
The Fertile Desert,

The Fertile Desert. |
| To the unscientific man it is one Of the
| riddles Of nature that where there is not
enough rainfall for agriculture without
irrigation, the soil is richer than in re-
gions where the rainfall is abundant
Take a piece of dry prairie land in Mon
| tana or a piece of the desert in Arizona
and turn on the water and forthwith you
have acres that yield far more abundant
ly than land in such humid states as Min
nesota and Wisconsin with their sup
posedly fertile SOIL
So great is the difference that many Of
the most important Of the worlds civiliza-
| lions have arisen in arid countries. That
is true Of Asia, true of Africa. 1t was not
the forest inhabiting Philippians that
reared Africa's greatest civilization but
the inhabitants of arid Egypt. The arid
belt extends from Egypt and Arabia to
Palestine, Syria, and Persia and across
the Indus and through the regions where
ancient Indian civilization reached its
pinnacle. In our own hemisphere it was
not the Indians of the forests but the Az
tees Of arid Mexico and the Incas of dry
Peru that had accomplished the most in
the advance toward civilizations. The re-
mains Of ancient irrigation works. and
populous cities in our own arid southwest
testify to a. higher state of social eff
cheney than ever existed in our wet for
est, country. 49,.
In an article in the September North
American Review, E. w. Hilgard, profess
sor of agriculture in the University Of
California, explains why it IS that the dry
country is fertile and the humid country
comparatively infertile. In brief the arid
) lands are fertile because Of the absence
) of rainfall, and the humid lands are less
| fertile because they have rain. There is
thus presented the paradox that though
the barren lands are actually barren be-
cause they lack rain. they are potentially
fertile because they do not have it. ~-..
The explanation is that where there are
J abundant rains the plant foods of the soil
are leached out, thus impoverishing the
soil. The soils water-soluble compounds,
, chiefly of sodium and potassium, cal
l cium and magnesium, are leached out Of
the land and passing through the sub
z drainage eventually reach the rivers and
! the sea. But where there Is little rain
fall this teaching takes place only partially
or not at ALL Sometimes there is not
r enough teaching in arid lands. Then the
salts, including the injurious ones, are re-
tanned and the "alkali'' lands result. The
excess Of soluble salts thus stored up for
- plant food in arid countries permit cult
walton, after irrigation is introduced, for
long years without the necessity Of re-
-, sorting to fertilization. 1t is we'll known
: that when the semi-arid region Of the
-. United States and Canada receives an
extraordinary rainfall crops are raised
that far surpass in yield those of dis
- tricts that enjoy greater mean annual
rainfall With a good year lands in the
- semi-arid parts of North Dakota distance
), the famous Red River valley in product
iveness. In the semi-arid regions Of Can
n ada where, usually, barely enough rain
O falls to-grow the wheat crop, land that
has been cropped for many years shows
no signs Of depreciation in fertility.
The soil ingredients that are drawn
d upon by crops to such an extent that they
ID require replacement, fertilization, thai
l. is, are potash, phosphoric acid, nitrogen
ID and lime. Potash, lime and nitrates are
j. more plentiful in arid than in humid
r. soils. Phosphoric acid is not more abun.
r dant. Thus in three important soil ele
Al ments the arid lands have an advantage
le tage.
n In quantity as well as in quality the
" arid soil surpasses the humid. All soil:
Of are formed from the disintegration o.
er rock. When rock weathers under arit
,e conditions, very little true clay is formed
at Consequently there is little difference be
es tween the arabic surface soil and the sub
7e SOIL sometimes to depth of ten fee
I'D or more. Air as we'll as water can easil.
IS, penetrate the powdery soil to grea
ut depths, and the roots of plants follow
TX them. AS Professor FIilgard puts it
IS ''This means that instead Of two or three
r. feet from three to five times that amour
of soil mass is ready to be drawn upol
~ by plants; so that the purchaser of
given surface area Of land really obtain
OF in the arid regions several times as mucl
in productive land as he would have re
ceived in the humid
A. These facts explain why a smaller trac
90 OF irrigated land is equivalent In produc
tive capacity to a much larger tract O
r nonirrigated land in the humid region
to They give added significance to natfona
irrigation work A hundred million acre
m of desert or arid land redeemed, is capa
bic Of supporting the same population a
In 400. O0O, 900 acres Of humid land. So whe