The Hawaiian gazette., 1909-08-17


tilzer was necessary. But both chem
zeal and field tests failed to show that
such was the case. But the chemical
Investigations did disclose the fact
that the black soil contains very
high percentage of manganese, and
that it is this substance which is
largely responsible for the yellow color
in the pineapple plants Careful ex-
aminations were made, and it was as
cer;ained that each sample tested con
tanned from ten to fifty times as much
manganese as did specimens of red
soil.
Manganese has long been credited
with being h plant stimulant, but the
experiment work at Wahiawa has dem
onstrated that it may often over
stimulate plant, by so increasing its
normal activity that the chlorophyl of
the plant becomes oxidized or bleached,
hence the yellow color.
The application of an acidic fertil-
izer, which contains large amounts of
readily available plant food, seems to
overcome this. The experiment station
is undertaking to ascertain the funda-
mental reasons why this takes place,
what the influence of the manganese
is on the other constituents of the soil
its nitrifying power, and so forth.
While the work has not reached com
pletion, it is safe to say that the black
soil may be treated in such way as
to render it exceedingly fertile.
The black color of the soil is not
caused by the humus which imparts
this color to soils elsewhere, but the
manganese. 1t may be safely stated
that no such extensive areas of this
soil, as are to be found in these islands
exists anywhere else on the face of the
globe.
Fertilizers were applied last Septem
Der, but the results did not begin tt
become patent until the warm weather
set in. Then the fruits of the expert
ments began to show themselves.
The chief characteristic of the frui
in the black, unfertilized soil, is tn,
pinkish color, and the. fact that it il
sour and devoid of flavor. On a piec,
of this soil where fertilizer has beer
applied, the plants are yet somewha
yellow, but the fruit is normal and tn,
production is estimated at about tel
tons to the acre.
On the red soil each subsequen
planting has resulted in a decrease,
harvest. Largely on this account tn
experiment was undertaken. Result
indicate that the liberal application o
high-grade fertilizer will materially in
crease the growth.
But the experiments now indicat,
that fertilizers will not serve as ;
panacea for every pineapple i'll. TIL,
pineapple plant is VIGOROUSLY sensitiv,
to adverse physical conditions in tn
soil. The soils here contain large per
centages of ferric-hydrate, which, to
gether with the clay in their compost
ton. enormously increases their water
holding power.
In the times of heavy precipitation
which are frequent in the Wahiaw
district, the soil becomes thorough
saturated with water, and this water
tenaciously held and prevents nitrifcs
ton. This brings about a conditio
which pineapple plants can not endure
In manv of the fields which are mad
up of red soil, there are found plan
which turn reddish color and die. Thi
is especially true of fields which hav
been cultivated for some years. Nj
Kelley has found that these plants ar
surrounded by water saturated soil.
The continued cultivation of pine
apples on this land has been foun
to hasten the oxidization of organi
matter in the soil, and with the deplt
ton of organic matter. The soils cor
tanning such high percentages of ferriC
hydrate are soon reduced to a stat
where drainage is greatly interfere
with.
Moving water is not detrimental t
pineapples, but stagnant water 500
brings about the death of the plant.
A series of experiments is now bein
, planned with the view to securing be
ter drainage. That the growers hav
recognized the necessity for improvin
the drainage, is evidenced by the intr,
: duction of open bitches at short di
tances in the fields.
1t is believed that the perfection {
! drainage systems, together with the il
PRODUCTION of more organic matter, wi
, bring about a better condition in II
, soils.
Proof of these contentious has bee
secured in the experimental patches, fC
!, on the better drained portions, fertili
ers which are proving of little vail
! on the poorly drained stretches a
? showing fine results.
, Experiments are soon to be cor
+ menced whereby leguminous crops wi
! be introduced. These will be plowe
under, and in this way the organic ma
ter in the soil will be materially il
E creased.
: OBSERVATION-DISCLOSURES
.