Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1914-01-13

deg G. was found to bring about an
increase in the water soluble man
ganese. lime. magnesia. phosphorie
acid, snlphates and bicarbonates. At
this temperature an increase In the
solnbiIity OF potash. silica. and alu-
nina vas produced in about so per
cent Of the soils examined. but q de-
crease was observed in the solubilt
" OF these elements in some in
stances. The solubility OF iron was
decreased In most instances
Gal Heating to ESQ deg. C. or ig.
milton produced effects ON the solu-
biIity in water similar to those
brought about at 100 deg. c., but
varying in degree, these being some.
times greater, sometimes less IN in.
tensity than those produced at 100
deg. G..
{5) The solubility in fifth-normai
nitric acid was not greatly affected
by heating to 100 deg. c.. but in some
instances heating to ESQ deg. G. con.
siderably increased the solnbility OF
alumiIa, manganese, potash, and
phosphoric acid and at the same time
effected reduction in the soluibility
OF lime and magnesia. Upon ignition
the soluhility OF silica, alumina. pot.
ASH, phosphoric acid and sulphates
was increased, while the solubility
of lime and magnesia underwent q
corresponding decrease.
(6l The soIuhiiity OF soils used in
aquatic agriculture Is abn0rmally
hIgh, but upon drying out, these be-
come much less soluble and approach
Il - kfes n
liaerated soils. When such soils are
heated after drying they seem 10 I'M
dergo changes of the same order as
are produced in dry-land soils.
| Cd No single factor is sufficient to
cover the solnbility effects resulting
from heating Hawaiian soil. On the
other hand, the subject is very COM
plex and involves many factors.
Among the more important Of these
may be mentioned hocculation, deoxi.
dation OF manganese, dioxid, oxida-
ton, particularly OF iron, double de-
composition, dehydration. and the at
tending physical alterations Of soil
films. Such alteration would destroy
film pressure, thus allowing the sol.
vent to come into more intimate con-
tact with the soil constituents. At
| the higher temperatures bicabonates
become converted into normal carbon
ates, thus effectively lowering the so
| lubility of lime and magnesia.
| go Nitrates undergo decomposi.
ton with heat, decrease in nitrate
content having been found to take
place at $50 dec. c., while at 200 deg.
or $50 deg. c. practically total de.
struction of nitrates took place.
| go One Of the noteworthy effects
OF soil heating is the production OF
ammonia, which at 200 deg G. was
formed in abnormally large amounts.
Soil subjected to heat from brush
burned in the field was found to nm.
sdergo stimulated standardization aft.
er heating Nitrifcation, on the other
hand, was not restored after the lapse
iof two months.
(10l Heating to 200 deg. G. caused
a loss of approximately Is per cent
of the total nitrogen A loss Of nj
trogeh and the ammonia formed by
the action of heat came largely from
the monamine acid group, while the
amids and diamino acid sustain
ed much less loss.
/ (11) The results Of these studies
are believed to throw important light
on the subject of soil aeration and
consequently have a direct bearing on
/ the practical question Of soil manage
ment.