Dec. I, 1885.] THE TROPICAL AGRICULTURIST. 



405 



expects to liitve 2.jO acres under crop next season. 

 Tlie Daly Kiver Plantation Company are vigor- 

 ously i)lantint; tlicir nursery for next season's rat- 

 toons ; they are also trying other tropiial pro- 

 ducts, — South Austruliiiit iieyiittfi'. 



TKA XIANUKES. 

 Bv Mil. John HccHfis. 



Experiments with 15oxE-i>rsT axu Castob-pooxac. 

 Analytical Laboratory. 7'J. Mark Lane, 



London, K. ('.. <»th Oct. l.s.sr,, 



I have carefully read the interesting account of 

 Mr. v. Carter's experiments with the abovenamed 

 manure!^ as published in the Tri'pudl Aiin'riiltiiri^t 

 (see pafje Hll|. and have no doubt that the 

 elaborate and detailed calculations in reference to 

 the results obtaine<l thereby have long since been 

 duly criticized by many experienced planters in 

 Ceylon as well as by numerous fellow-workers in 

 India, 



The general opinion will probably be that the 

 increased yield of made tea was not sutlicient to 

 compensate for the heavy cost of manure, and 

 that the outlay of I{(>3 in one case and as much 

 as R70 in another experiment is far too great, if 

 any, substantial profit is to be made from the estate. 



The experiments however, so far as they go, are 

 highly suggestive, and the author deserves the 

 gratitude of planters for publishing his results. 



It is [K-rhaps a matter of regret that the two 

 experiments were not made more directly repre- 

 sentative of htiiu^-ditst as opposed to i-ttstitr-pofnuir^ 

 each being used separately ; instead of a mixture 

 Oi these two in plot 2. and an innnense dose of 

 castor-poonac in plot 3. 



It will be remembered that in plot 2, IM cwt, 

 of a mixture consisting of one-third bone-dust 

 and two-thirds castor-poonac was applied per 

 acre, the result being an increased yield equal to 

 liKi lb, of made tea, as ojjposed to an increased 

 yield of 2M"» lb. from plot :i. where 24 cwt. of 

 castor-poonac alone were applied. 



If we assume that, for the extra <i cwt. of 

 |K)onac, there was an equivalent increase, as com- 

 pared with la cwt. (if such had been used over 

 a separate ]>lotJ, \vc can reduce the increased 

 yield of 2S5 lb. to 214 lb. ; and this result would 

 still compare very favourably with that from 

 ))lot 2 where the mixed manure was used as stated 

 at the rate of IS cwt. and cost KfiO, whereas 

 the IM cwt. of castor-poonac would only cost E-i2:',. 



He this as it may, theic can be no doubt that 

 the general result of these cxi)eriuients suggests 

 that castor-poonac is, weight for weight, a more 

 remunerative manure for tea during the first year 

 or two than ordinary bone-dust, but whether the 

 results are likely to be so lasting, is, of course, 

 another matter and remains to be seen in the 

 future crops 



Mr. Garter does not state anything res])ecting 

 the composition of the mateiials used, but we 

 may conclude that the bone-dust was of good 

 quality, coritaiiiing .50 to r>2 per cent phosphate 

 of lime and H-70 nitrogen ecpial to 4i of ammonia. 



As regards the castor-poonac. it is important to 

 know ttliitlier the white rich cake containing as 

 much as 7 |)er cent of nilrogi-n was used, or the 

 coramou brown cake wliich only contains 4. J of 

 nitrogen jwr cent. 



In Comparing the relative advantages of castor- 

 poonac and bone-dust we must icmember the 

 character of the crop we jjroposc to take otV tlw 

 land. As I have already shown in my original 

 urlicle on tea iiiamnes, nitrogen is tlie element 



which is most required ; next conies potash; then 

 phosphoric acid ; and lastly lime. Now in every 

 100 parts of the white castor-cake we tind at 

 least 1)0 parts of nitrogenous and carbonaceous 

 organic matter containing from 7 to 7A parts of 

 actual nitrogen which on deconqiosition will be 

 equal to from 8,J to 'J per cent of ammonia, 

 while the renniining 10 jmrts of mineral matters 

 are speciall> rich in potash and phosphoric acid 

 in a form admirably adapted for assimilation by 

 the young rootlets of the tea bush. 



If brown castor-poonac is used the percentage 

 of nitrogen is only from 4 to 4.^ per cent on 

 account of the largpr proportion of husks left in, 

 while the amount of mineral matters is also re- 

 duced in proportion. In bones however we have 

 only .'!;! ])arts of organic matter yielding 8-70 of 

 nitrogen in every 100 i)arts, while the mineral 

 portion is as much as (17 parts containing at 

 least oO per cent of phosphate of lime in a com- 

 paratively hard condition so that some years are 

 required before the full value of the fertilizing 

 elements can be utilized as plant food. Lastly, the 

 proportion of potash in bone-dust is very small 

 and cannot be considered as a ready source of 

 sujiplying this element. In conclusion I may re- 

 mark that it seems much more reasonable to ajiply 

 a moderate dose of manure every other year, than 

 to give 24 cwt. of a highly rich nitrogenous 

 fertilizer one year and to allow the tree to suffer 

 from famine during the next ten years, which would be 

 especially trying under a stimulating climate. Where 

 we have a poor soil and an exhausting climate 

 it appears imperative to apply manure in small 

 doses, year, by year or at least every second year. In 

 days gone by there have been plenty of examples 

 in Ceylon alone, when over-manuring has very 

 materially contributed to the i)rcmature abandon- 

 ment of many good coffee estates. 



In regard to tea it may therefore be well to proceed 

 carefully in this matter, and to be on om' guard 

 against producing a coarse quality of leaf, wliirh 

 would certainly be the result of too nuieh manure. 

 Used in moderate quantity I have every hojie that 

 castor-poonac will be found a most excellent nuiinn'C 

 for tea. 



TEA PLANTING IN CEYLON. 



Extract from Mr. Irvine's letter dated Awisa- 

 wella. 20th October lrtH.5 :~ 



You nuiy put the following remarks down as 

 general and simple axioms: — 



1st. Tea, though a hardy plant, recpiires more 

 care and skill in cultivation than cott'ee. 



2nd. Tea will frequently be found to grow well 

 on soil not adajited for coffee, or on worn out 

 coffee land. Tea however will not grow well or re- 

 innneratively on every poor soil and frequently not 

 well on soils commonly supposeil to lie rich, (rood 

 soil will tell both in the yield and (juality of the tea 

 as with any other ]ilant -the better the soil, tlie 

 better the tea. 



;h'd. The quality and tlavor of the tea will vary 

 with the soil, aspect, climate and elevation : no two 

 estates will ju'oduee the same tea. 



Itli. 'J'lic cultivation nnist vary or be adapted to 

 the clinuilie and othei- eotidilioiis of eiieh rlistrict. 



oth. What is commonly c:.lli'<l the jiit of the 

 plant is not sullicieiitly considered with reference to 

 climatic and local couditiotis, piiucipally of elevation 

 and soil : a variety of tea good on unr estate nniy be 

 worthless on another. 



tith. Climate, soil, asjiect and elevation are 

 already having a most marked cITrct on the tea ]ilant; 

 a few years hr-nee the acclimatized ten plant of 

 Ceylon will have its well deliiied and distinct 



