THE TROPICAL AGRICULTURIST. 
[June i, 1898. 
856 
the most readily, then cake, then dried blood, and, 
last of all, Sulphate of Ammonia, which uitiified 
very slowly. The rapid nitrification of fish guano 
explains why tea responds so readily to this manure. 
Boname remarks that “probably nitrification is 
assisted by the presence of Calcium phosphate and 
carbonate in the orgauic mariures.” Certainly, when 
chalk was added, along with the nitrogenous manure 
hitrification was hastened in every case, the order 
of nitrification being then sulphate of Ammonia, 
dried blood, oil-cake ; no experiment with fish guano 
being recorded. I note, however, that in this experi- 
ment the chalk was added in very large proportion 
viz. 5 per cent, of the soil. The slow nitrification 
of Sulphate of A.mmonia in the absence of carbonate 
of lime, and the beneficial results obtained by its 
application to crops, are regarded by Boname as 
supporting the view, that, under some conditions, 
plants can directly utilise saUs of Ammonia. Seeing 
then that lime, or carbonate of lime, hastens nitri- 
fication, and liberates potash, an explanation seems to 
be required why the general experience of tea plan- 
ters is unfavourable to the liming of tea soi's. 
The only chemical reason which suggests itself to me 
is, that, by liming, the available phosphoric acid is not 
increased pari passu with the potash and nitrogen. 
Little, therefore, of the extra potash will be utilised, 
and much of the nitrogen wasted as, when nitrogen 
has been turned into nitrate of calcium, it perco- 
lates through the soil gradually, and is lost with 
the drainage water. Mr. Baur, whose articles on 
manuring have been read with much interest, 
is quite correct in his view that by the use of 
phosphate and of potash in readily available forms, 
the proportion of nitrogen in manures may be 
reduced. This may be regarded as a general prin- 
ciple in manuring; and, now that soluble phos- 
phates and salts of potash have been brought within 
reach of the planter, it ought to be made matter of 
experiment how far the general principle enunciated 
is applicable to a perennial leaf-crop like tea. 
Several of the experiments with Thomas’ phosphate 
powder suggested in the pamphlet published by 
Messrs. Freudenburg & Co. have this for their object 
to see how far the nitrogen in tea manures may be 
reduced by the use of Thomas’ phosphate powder and 
sulphate of potash ; thus, four of the experimenta.1 
mixtures contain each only about two-thirds of the 
amount of nitrogen commonly used ; one contains 
only one third of the amount, and one contains no 
nitrogen at all. 
Mr. Baur’s fertilizers for tea, supply phosphoric 
acid in a different, but very available foim, to- 
gether with salts of potash ; and, although the 
nitrogen is in much smaller proportion than in 
the tea manures commonly used, it is, neverthe- 
less, greater in amount than in the manures recom- 
mended and used with success for cereals, which 
take up fully as much nitrogen from the soil 
as average crops of tea. The great advantage of 
phosphates soluble in water is their initial diffusi- 
bility through the soil. They gradually relapse into the 
less soluble forms, but, in a very fine state of division, 
readily acted upon by the acids of the root fibres or 
hairs. I might cite one instance which appears to me 
to tell in favour of using more available phosphatio 
manure than bone-meal, together with a re- 
duction in the proportion of nitrogen in 
manures. A short time ago, I had a soil 
to analyse from a very fertile tea estate, yielding 
in years of good rainfall over 1,000 lbs. dry tea per 
acre. I naturally expected to find this soil very rich in 
nitrogen ; but, on the contrary, the nitrogen was 
scarcely of average amount ; but the soil was rich in 
phosphoric acid and potash. The soil was a fine red 
soil, containing a good deal of oxide of iron and 
alumina; and, although the soil was in a fine state of 
division, it allowed water to percolate through it with 
sufficient freedom to ensure very good aeration. It 
was a soil evidently well fitted to utilise the natural 
supplies of nitrogen. 
M. COCHRAN. 
TEA MANURING. 
Central Province, April 28. 
Dear Sir, — You invite attention to the recent coitc* 
spondence and circulars of the Manager of the Cey 
Ion Manure Works ; and it is somewhat remarkable, 
considering the vital importance of the subject, that 
you have not had ample pabulum to deal with in your 
columns. Too much time has been given to useless 
discussion of Exchange and Currency questions, and 
now Wars and Plague are likely to distract busy plan- 
ters. And that word ‘busy’ reminds one that probably 
the men whose opinions are most worth having, from 
their extensive experience, are the very men who 
cannot spare time for newspaper correspondence, valu- 
able though it is at times to our community. However, 
I venture to try and lead the way, in the absence of 
others better qualified, and hope some useful results 
may be attained. 
And firstly it may be taken for granted that if Go- 
vernment will not assist us with an Agricultural 
Chemist, the P. A. should take up the question 
thoroughly. Having agreed to pay for the analyses 
of the cacao tree to assist cacao planters in deter- 
mining the best manures to use, it should extend that 
principle to tea. Certain well-known tea gardens al- 
ways secure stand-out prices, owing to the flavour, 
point and strength of their teas. Let these be ana- 
lysed and compared with analyses of medium and 
low-grown in Ceylon, and let the analysis be a 
thoroughly exhaustive one. It is amply proved that 
elevation alone will not account for the superiority 
of high-grown teas. Climate certainly accounts for 
much, and if the micro-organism theory of nitrifica- 
tion is proved true for the tropics, then one can 
understand gardens in sheltered valleys with mode- 
rate rainfall and a fair share of sunny skies suffer- 
ing less in periods of drought than estates in ex- 
posed, cold, wet and cloudy situations, the absence 
of extremes being favorable to growth of these orga- 
nisms and consequent ample supply of nitrogen. To 
a certain extent a judicious selection and distribution 
of shade trees and wild belts will moderate the effects 
of both cold damp and extreme drought, and legu- 
minous trees would undoubtedly add to the sources 
of nitrogen. The absence of red-rust too is often 
most marked under certain shade trees, e.g., some 
albizzias and jak. Trenching in shade loppings (where 
lay of land permit) mana grass and young-lantana 
would also improve mechanical conditions besides 
enriching soil. Personally I believe the less we use 
artificial manures the better ; but in many cases they 
are absolutely necessary for many palpable reasons. 
How far the quality of the soil influences flavor has 
yet to be discovered, also how far jat is accountable. 
I know of two g-ardens which were planted almost 
entirely from Indian Indigenous, or the old Horagalla 
seed, and for some time stand-out prices marked these 
places, but in the latter case it is no longer the 
happy experience now ; and in the former the prices are 
rapidly approximating the general average of the dis- 
trict notwithstanding every advantage of soil, climate 
and well-equipped factory. There seems good reason to 
believe that young tea in new soil will always give 
better flavor especially in the higher districts. But 
in the lowcountry I fear the cause of inferiority is 
incurable, owing to the too rapid growth of flush 
not allowing time for the mature elaborating of all 
the elements needed to give a strong well-flavored tea. 
Experiments with Baur’s and Freudenberg’s 
manures should be undertaken at different elevations. 
The Kirkoswald experience is valuable for that dis- 
trict ; but it is a question whether it would be equally 
satisfactory in Kelani or Kalutara. 
Can any of your. readers give us the results of using 
“Basic slag?” (Thomas’ phosphate powder). Iron is a 
capital tonic, and it should prove a powerful vege- 
table stimulant in a phosphatic form. 
On the principle “ train up a plant in the way it 
should grow ” the importance cf the subject of manur- 
ing can hardly be exaggerated. ’Tis all very well to 
advocate finer plucking but personally I should com- 
mend more careful plucking, which need not necessarily 
