Evening bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1895-1912, 1901-11-30

washed out by waters OF irrigation. rhOs-
pilates are readily retained owing to the
lime content Of the coral sand. 1t was rec
commended that phosphates, blood, sulphate
of potash land sulphate Of ammonium In
small auantities) be used, and this recon-
mendation is being carried out both on the
Kahuku and Kihei plantations. Both II
these plantations now use two different
formulas, one for the rich, red soil and he
other for the sandy soil.
In conclusion, It might be stated that the
general tendency is toward the use OF more
soluble fertilizers, a larger quantity Of pot
ash and ammonium compounds and less
phosphoric acid, especially when In the
form of bones or undissolved phosphates.
The planter sees that the freight on q ton
Of low grade fertilizer is the same as on
ton Of high grade, and being so far away
from the sources Of supply 1t Is economy
to use the most concentrated goods.
These changes have been followed by
splendid results. It is wellknown fact
that the yield OF sugar per acre has enor-
mously increased during the past few years.
Six years ago the average for the islands
was $500 pounds Of sugar per acre, while
now 1t Is four and q half tons per acre. OF
course a more careful cultivation and
great improvements in mills have added
their part In this improvement; and we must
not forget that the alert, intelligent man
agement Of the plantations, which 10 at the
very foundation Of the recent enhanced val.
ues Of the sugar properties, has made It
possible for these increased yields. But GER
tainly, after all is said, commercial fertiliz.
Methods Of Soil Analysis.
The ordinary agricultural analysis is still
used, and, with a careful Interpretation,
gives indications Of the needs Of the soil.
The aspartic acid Of the Hawaiian Expe'i-
ment Station Is also quite often used, AMI
seems to give good indications of the COIL
dition of availability Of the potash AMI
lime. But 1t Is doubtful II the method Is
applicable to phosphoric acid. According
to the method there are extremely small
quantities Of available phosphoric acid Ia
any Of our soils, which COMFORTS with our
belief that It is locked up with the titanu11
and iron and aluminium; and yet the app,i.
cations Of phosphoric acid have not been
attended by a large increase of sugar. In
deed, as has already been stated, the ten
dency Is to decrease rather than to increase
this element In commercial fertilizers.
The quantity Of fertilizers applied per
acre varies considerably. The average is
probably 800 to 1000 pounds per acre, while
In cases 1t varies from 500 to 1900 pounds
per acre. This, 1t Is to be remembered, is
In addition to whatever nitrate Is applied,
which Is looked upon as stimulant.
Nothing thus far has been said concern.
ing the elements withdrawn by the crops
from the soil, and 1t would seem that our
methods OF fertilizing do not take this into
account. 1t has long been favorite theory
with agriculturists that we should return the
exact quantities Of elements that are with
drawn by one crop, and chemists have been
to great pains and expense to analyze all
agricultural plants with a view to COM
pounding for each crop fertilizer that will
supply this drain. Looked at casually, this
seems to be correct theory, but It does not
bear close investigation. 1t aoes not take
into account the fact that the elements in
the soil are not available In the exact ratio
Of their removal by the crops. and that the
rocks are being disintegrated constantly and
yielding up plant food In very different ra.
tios in different places. A consideration If
the chemical composition Of Hawaiian lavas
from which the soils are derived will show
this.
Lime in Hawaiian lavas (see Maxwell:
Soils and Lavas).
Non-hydrous lavas ..9.24 per cent
Hydrous lavas .... 1928 per cent
TuIas Ill per cent
Evidently the resulting soils would differ
very materially In their content of lime, and
any system of supplying lime to the soil that
does not take these differences into account
Is wrong. Likewise the potash and phos.
phoric acid differ very essentially In these
rocks and consequently in the soils. Again,
the rains percolating through the soil car.
ry on these elements In very different pro-
portion. Maxwell: Lavas and Soils. page
lv-, says I'm the passing, over of lawns
into soils there have been removed eight
tons $50 per cent? out of every nine tons Il
lime; one-half ton (33 per cent? out of every