The emigrant aid journal of Minnesota. [volume] (Nininger City, Minn. Terr. [i.e. Minn.]) 1856-1858, 1857-09-26
Stow Drouth Benefits the Soil.

That a season of extreme drouth-so often occurring
and 50 injurious TO our summer crops-should still prove
beneficial to the soil, seems strange, but chemical science
shows us that drouths are one of the material causes to
restore the constituents of crops and renovste cultivated
soils.
Miners! matter is taken from the soil by the crops
grown upon it, and also carried away by the surface water
flowing into streams, and thence carried to the sea.
These two causes. always in operation, unless counter.
&C ted by other influences, would in time render the earth
a barren waste. The diminution which arises from the
first cause is in part restored by manures, but not in all
cases. and Providence has provided a way of its own ia
supply lost mineral constituents needed in the growth Of
plants. AT intervals drouths occur to bring up from the
deep parts of the earth food for the use of plants when
the rains shall again fall.
The manner in which drouths exercise their beneficial
influence is as follows: during dry weather a continual
evaporation Of water takes place from the surface of the
earth, which is not supplied by any from the clouds.
The evaporation from the surface creates a vacuum Gas
far rs the water is concerned) which is at once filled by
water rising up from the subsoil the water from the
subsoil is replaced from the next below, and in this man.
ner the circulation Of water in the earth is the reverse
of that which takes place in wet weather. This progress
to the surface of the water in the earth manifests itself
~strikiugIy in the drying up of springs and wells, and
streams which are supported by springs.
1t ia not, however, only the water which is brought to
the surface of the earth, but also all the water holds in
solution These substances are salts of lime and mag
nesia. OF potash and soda, and indeed whatever the sub.
soil or top strata of the earth may contain. The water
on reaching the surface, is evaporated, and leaves behind
in the soil its mineral salts, the chief Of which are imsy
magnesia, phosphate of lime, ~sulphate..o of lime, carbonate
and silicate Of potash and soda, and, also, comuon salt
AL indispensable to the growth Of the vegetable pro-
ducts Of the farm. Pure rain water, a. it alls, will dis
solve but a very small portion Of some Of these sub
stances, but when it sinks into the earth it then becomes
strongly imbued with carbonic acid from the d~ecomposi-
ticn Of vegetable matter in the soil, and thus acquires
the property of readily dissolviug minerals, on which it
before could have very little influence.
Several experiments tried by Professor Higgins 60 to
show this action of drouth in bringing matters to the
surface Of the soil. 10 one case he placed q solution OF
chloride Of basinm in the bottom Of a glass cylinder,
and then filed it with dry soil. After long exposure to
the rays of the sun, the surface of the soil was tested
will, ~sulphuric acid, and gave a copious p~recipitate Of
sulptate Of taryta. Chloride Of lime, sulphate Of soda
and carbonate Of potash were experimental upon in like
manner and upon the application Of proper tests, the
surface Of the soil showed their presence in large quanti
ties, drawn up by the rising Of water from underneath
a, il the case Of drouth.
The parclt,I e,rth-every green thing dwarfed u
growth Or withcred by long continued heat-seems sui
fering under an affective dspensation Of Providence, ye
we should not murmur it is a blessing in disguise
IRE Early and tic latter rain may produce at once abun
iant crops, but dry weather is needed to bring TO thu
surface food for future harvests from the depths Of til,
earth, where else it would lie forever unemployed. II il
a needed means Of keeping up the fertility Of the cult
waited soil.