Evening star., 1938-09-27
OF STARS,
MEN AND ATOMS
Notebook of Science Prosres,
in Field, Laboratory
and Study.
r. THOMAC p HENRY
By THOMAS r. HENRY.

0As>S 0SSSye
By THOMAS r. HENRY.
An obscure element, present in the soil
IN almost inflnitesimally minute quanti-
ties, Is absolutely essential to normal
plant growth and constitutes vital fac
tor in agriculture.
This element, according to reports pre-
sented before the recent meeting Of the
American Chemical Society, is boron. It
seldom Is found in greater concentration
than one pound to a million pounds of
soil. II 1t Is much more abundant 1t
changes from q life element into death
element, proving serious poison to vege-
tation.
Plants require boron, 1t was reported,
In the same way that animals require
certain foods and vitamins. This recent
discovery has led to more than hundred
research projects at experiment stations
all over the world In the past three years,
since the significance Of the element to
agriculture became established.
The amount required for normal plant
growth Is extremely small. In most cases
1t Is not more than . few ounces per ton
Of dried produce. Recent researches
into the role 1t plays and on factors in the
soil antagonistic to it were described by
DR.. James A. Mattel, soil chemist Of the
University Of Alabama.
Lack Of boron in the past, it was ex-
planned, may have been the reason for
some mysterious crop failures which were
attributed to diseases the causative Or
ganisms Of which could not be found.
Boron deficiency often Stimulates some
sort Of fungus or bacterial malady which
sweeps through field.
It Is known to be essential for some
vegetables. When the whole story is
known, 1t was suggested, it may be found
vital element for all forms of vegeta-
ton. It is q factor which must hence
forth always be considered in fertiliza-
ton programs-one Of the most essential
Of group Of approximately dozen
elements necessary for healthy plants.
Boron, the report continued, might be
considered almost as miracle element
in plant nutrition. In the absence of
any Of this element in the soil the grow
ing point of the freshly terminated plant
dies, the roots fail to develop and the
conducting vessels within the seeding
decompose. The plant either dies or is
deformed. Yet one part of boron in from
100000 to 100000 900 parts Of soil mois-
ture is all that is necessary for normal
plant growth.
The discovery that boron was essential
was made In 1914, but was partly for
gotten In this country during the World
War. American potash salts were first
used during this period as a source Of
potassium in fertilizers, and it soon was
found that poisonous amounts Of boron
were being added along with the potas-
sium. Chemists proceeded to devise
methods Of getting the element out Of
the potash altogether.
Then it was discovered, seven years
ago, that the heart rot of sugar beets
was caused by a boron deficiency and
not by disease. This finding stimu-
lated investigators all over the world,
with the result that boron lack now is
recognized as the cause Of brown heart
OF turntpS, cracked stems Of celery, in
ternal cork Of apples, the browning OF
cauliflowers and the "yellows" disease Of
alfalfa.
The most recent discovery, 1t was re-
ported, was that adding lime to soils in
duced boron deficiency under some cor-
ditions. In highly acid soils, containing
little or no boron minerals, the correc-
ton of acidity by lining renders the
tiny amount present inaccessible to the
plants. In some instances this results
In q crop failure.
At first 1t was naturally supposed that
the soluble boron in soils was chemically
hxed In unavailable forms by the lime,
but this theory is weakened by the OBJ
servation that the condition does not
occur In all soils and also by laboratory
findings that 1t is impossible to precipi-
tate the boron in concentration 80 low
as are present in soils. Thought was next
turned to biological absorption and to
the possibility that the available boron
was utilized by the mcro-organism
which are known to increase tremend-
ously upon the addition OF lime to acid
soil. That is, there is competition be-
tween the micro-organisms and the
higher plants for the available boron
with the result that the latter fail to get
enough for normal growth.
Some proof Of the biological ixation
theory has been obtained, it was re-
ported, by the finding that sterile cul-
lures do not produce boron-deficient
plants and also that there is less fixa-
ton Of boron by lime in sterile cultures.
Among other interesting observations
| on the Ime-boron relationship was that
lining soils decreased the boron content
| Of crops, that acid-forming fertilizers
GeIAO 10 O11ScL LIE OVcIuIIlllR eucCC Wllllc
the reverse is true of alkaline fertilizers.
and that the greater the clay and lime
content of soils the greater the concen-
tration of boron which may be present
without producing toxic effect on the
plants.
Boron is present in soil in two forms,
| 1t was reported by Drs. K. c. Berger and
Emil Kruogg Of the University Of Wis
consin. One is in the form Of a mineral
| called tourmaline, unavailable for plants.
The other is In the form of calcium or
manganese borates, which can be abb
sorbed by vegetation. The two Wiscon-
sin chemists have worked out a method
during the past year by which from
small sample Of soil they are able to es-
innate whether 1t contains enough avail
| able boron.
The cost Of fertilizing with boron, they
estimate, is less than rs cents an acre.
| MariqO1ds.