The sun., 1903-12-08
PLANT FOOD FROM THE AIR.
Five years seo last September Sir William

'
Crooke in his famous address before the
| British Association, predicted universal
dearth Of bread in the next generation He
endeavored to show that the wheat pro-
ducing soil of the world is wholly unequal
to the ever increasing strain put upon it;
that the number of bread eaters had grown
from 37l 200, 900 in 1871 to 5l8,5OO 900 in 1893;
that the wheat growing areas could not
possibly increase in the same Ratio and their
production per acre was constantly declin-
ing because the nutrients required by the
| plant are not fully restored to the soil
There was only one way of salvation for
| hungry world. and that was through the
door of the chemical laboratory. All plants
must have nitrogen in order to thrive, and
nitrogen in a free state is one Of the most
| abundant substances in nature. Every
square yard of the earth's surface has nitro
| gen gas pressing down on it to the extent OF
about seven tons-but this is in the free state
and plants demand it fixed in the soil
Nitrogen was to be the fairy godmother
to save the world from bread famine, and
Sir William predicted that the problem OF
the fixation of atmospheric nitrogen would
be solved in a few years. 1t had already
been discovered that by passing strong
| inductive current between terminals the
air takes fire, burns with powerful flame,
and produces nitrous ard nitric acids
This discovery, he believed, was likely to
lead to the development Of a mighty indus
| try destined to solve the great food problem
| in spite OF the fact that barnyard fertilizers
are wickedly wasted. that guano has dis
appeared and that the nitrates OF Chile Will
become exhausted in from twenty to thirty
years.
The premises of Sir William and the food
scarcity he deduoed from them were stoutly,
and it is believed successfully. contested;
! but his striking prophecy as to the prac-
| tcability of the flxation Of atmospheric
nitrogen fol the purposes Of agriculture is
coming true, and it is matter of vast i'm
! portance to the farming and Other material
! interests Of every nation.
!, As plants cannot Use nitrogen as gas,
chemists and physicists are now making
every effort to devise mechanical means for
securing nitrogen from the air in fixed
form Very satisfactory results have been
obtained in the past two years by the Use OF
electricity, and the latest Yearbook Of the
Department of Agriculture says there is
good reason to believe that it will soon be
possible to place upon the market manu-
featured nit cate of soda or nitrate Of potash
that will be&,iperior in quality to the de-
posits found in Chile and will compete with
them in price.
But still greater progress toward the
same end is being ina de in another direction.
1t has been known for centuries that many
soils, living fallow for a considerable time,
gain in nitrates without tn" aid of any
manure or mineral fertilizer II was not
known till recent years that this increase in
nitrogen content is due to a few forms OF
soil bacteria which have the power of fixing
free nitrogen from the air and making it
available for plant food. In his annual
report for 1901 the Secretary of Agriculture
called attention to the discovery of new
method of cultivating these soil bacteria.
: In his report for last year he announced
! that the new method had been perfected
during 1902 and that the nitrogen gathering
1 power of the bacteria grown by this method
had been found to be five times as great as
that of the ordinary forms found in nature.
1t had been supposed that these forms Of
bacteria were naturally developed only on
the roots of leguminous crops such as
beans, clover. peas, lentls peanuts and
others; but it has been proved that they
have a much wider range of activity.
Not only methods of propagation but also
of the safe distribution of these nitrogen
gathering bacteria have now been per-
fected Within the past few months the
Department Of Agriculture has been en-
gagged in the wholesale propagation Of these
bacteria and in sending them to farmers
for the inoculation of seed crops. The
organisms are thoroughly dried and sent by
mail in small packages of absorbent cotton.
each package ontaining l5,OOo. 200 bacteria,
enough for the thorough fertilization Of an
acre. Immersion In water revives them
and they are then fed on nutrient salts
and multiply at an astonishing rate The
reports from cooperating farmers show the
most favorable returns from the Use of these
organisms.
Mr.. c. B. Lane of the New Jersey Expert
ment Station has q y in the American
/ Agricuiturist of Nov, zs the results OF some
experiments with these bacteria. He says:
| After the bacteria which grow upon any par
tcular plant have become well established In the
soil this soil can be used to inocuate any other
field by distributing In the manner fertilizer
= The writer has some experiments with alfalfa
In progress along this line. The soil In the plots
was lnoculaed by applying soil from an old alfalfa
led Wnlcl was known 10 contain an abundance
OF bacteria. The first cutting, which has Just been
. made showed gain OF is per cent. OF inoculated
plots over plots not inoculated the plots otherwise
, being treated the same. Other plots inocu lated
with solution made by mixing soil from the old
alfalfa cld with water showed gain OF IS per cent.
over plots not inoculated. II is believed from the
results thus far obtained that the method OF inoc-
Iatlng with soil from old lelds where the bacteria
have become well established will prove very
| practical.
A new wonder of science has been re-
vealed Through the agency Of these
microscopic organisms, l0,OO0OOO Of which
can he held in a thimble, it is now believed
to be perfectly practicable to draw from the
IS, 900 tons Of nitrogen that, 1t is estimated,
are suspended over every acre of land, an
abundance of the most vital element Of
plant food. thereby greatly increasing the
yield of crops and adding permanent fer
tility to the soil
ausdruplc the Appropriation for New
Ships OF War!