March i, 1883.] 



THE TROPICAL AGRICULTURIST. 



765 



low the public to be misled I have thought it better 

 to send you herewith the actual results referred to, 

 and also some later analyses : — 



OM 







^ "o ^ ca 



2 years 3-12 ms. original '93 "54 — 



„ 6 12 ms. renewed three nis. "69 '50 — 

 „ 7-12 ms. „ 4 „ 2-40 — "90 



„ 8- 12 m9. „ 5 „ 3-32 — -10 



„ 912 ms. „ 6 ,, 402 — -15 



„ 10-12 ms. ,, 7 ,, 388 — -55 



,, 11.12 ms. „ 8 „ 5-50 — "lO 



3 years „ 9 „ 4-96 — -10 

 3 years 1.12 ms. „ 10 ,, 5-33 — 10 



2-10 ms. ,, 11 „ 5-44 traces -IS 

 These officinalis were all planted in June 1879 and Were 

 shaved first in September 1881. It will be seen that 

 there is a steady and rapid increase in value up to 

 the sixth month's n-newal. After that, as far a'* my 

 experience goes, it is chufly a question of weather, the 

 bark shewing a higher percentage after a good spell of 

 dry weather ihan durins; rain. The value of these 

 sample^i, as quoted originally by your contemporary, 

 can be of no practical use, owing to the fluctuation of 

 tlie London market at the time these analyses were 

 made.— Yours faithfully, HUGH L. HUBBARD. 



THE TRUE VALUE OF NITRATES. 



[This letter is in continuation of correspondence on 

 "Nitrates" which appears on page 350. — Ed.] 



Udagama. 



Dear Sir, — I fancy your correspondent " W. D. IJ.'' 

 is right in suggesting the application of cattle dung 

 fresh, but is surely at fault in his reason — "if used fn-sh 

 from the sh'^d it is of little value on account of its 

 nitro;;eu, thi' proportion of that element at that period 

 being but trifling compared with the mineral"? — my 

 impression being that at no period does it contain 

 more : that the true explanation is that in fresh dung 

 the bulk of the nitrogen exists in an insoluble form, 

 owing, a-i ho says, to fermentation having but partially 

 taken place ; and that it is therefore less likely to 

 produce the not improbable etfects on the wood, dur- 

 ing wet seasons, or in a wet oliroate, more especially, 

 he fears may result from suddenly flooding the tree» 

 witli a superabuudanoe of at once auailnbl^ nitrogen. 

 And here to act as a regulator in preserving at a 

 desirable balance the soluble nitrogen I think the 

 value of a system of green crops, the same to be 

 destroyed and returned (turned in) to the soil at suit- 

 able intervals, is at once apparent. But in saying this 

 it must be taken as no unreserved suggestion, though 

 so good an authority as Liebig is answerable for 

 the idea ; nor ran I think of any serious objections, 

 if crops, readily grown, and under easy control, be 

 selected — crops not subject to rapid reproduction 

 naturally from seed, or root fragments, as in the case 

 of white weed and grass ! The latter (grass) I regard 

 as to the last dtyree objectionable; and I am sure all « ho 

 have had to ileal with a certain small species known in 

 Tamil as "era pillu," and who are not desirous as a 

 change to see their propprties converted into per- 

 manent pasture and the foliage of their coffee into 

 imitation i/olrUleaf, will agree with me ! A root crop 

 which ciiuld possibly be killed as it stood by a prick 

 from a pointed stick dipped occasionally in carbolic 

 acid as rapidly as are dandelions by gardeners at 

 home, or perhaps better still the crop you s>Ui;gested, 

 " rai>e, " would be free from these objections : and not 

 only Would it possibly accumulat' ad-Iitional nitrogen 

 from thi- atmosphere, a-i ilo legiimhioux crops, c'lcck 

 waste by nitrification .and losses by wa^h, as well as 

 retaining meisture in the soil in dry we.ati er, bill -ill 

 97 



superfluous or extraneous supplies taken up would 

 be stored in the green crop itself, in the form of 

 insoluble nitrogen, till .again rendered soluble by its (the 

 green crop's) decay. Thus continually during years 

 of sh'U't harvest would the latent richness or "con- 

 dition" of the soil be preserved, and increased :— an 

 accumulated richncsa in nitrogen that,I feel sure will 

 be found none too great when, hereafter, he ivy crops, 

 be they of what they may, have again to be support- 

 ed ! It might even be tlie moans in time of enabl- 

 ing your correspondent to supply his old cott'ee suc- 

 cessfully, if I understand him rightly to 6,ay that 

 a deficiency of nitrogen in the surface soil is the 

 reason in his opinion why they — aijd why cinchonas — 

 do not come on well on old, long-exposed land : 

 at any rale the fact that my metapJmrical beef, 

 " white castor cake," has usually bem found the most 

 successful application in bi'ingiug on the former, would 

 support this view. 



I particularly guarded against saying, as implied, 

 that he placed no importance on nitrogen. He uow 

 directly taxps me with placing too much ! This 

 I most emphatically dispute, and must repeat my firm 

 conviction that he places far too little on it, if pre- 

 pared to sacrifice, as he allows, any of our natural 

 supplies, if they can be economically secured and 

 preserved. But when further he attempts to inculcate 

 the theory that heavy crops are to be kept up per- 

 manently, or for a lengthened period, on plain bones 

 or mineral manures with 1U> larger a percent'ige of 

 nitrogen in them, it is, I think, to tlirow it in the face 

 of an accumulation of ungainsa.vable experience in the 

 past, and of the opinion of the several professional 

 experts who have given the subject as regards coftee 

 their attention. I am not doubting that u any an 

 estate has been judiciously, and with cxcell-'nt and 

 no damaging results, manured with plain bones, or 

 phospates, after a previously light crop, or 

 wliilst in excessive good heart ; and neither 

 am 1 doubting the advantage of applying other 

 necessary ingredients there may be a deficiency of, 

 independently of nitrogen ; or that, on the other hand, 

 wast-, and perhaps a lessened crop, may have occasionally 

 occurred through an excessive or injudicious use of 

 nitrogenous manures. But I fancy there are few 

 . planters of lengthened experience out here who will 

 not record it as the result of their observation that 

 the application of plain bones, unless as coarse as gmvel, 

 could only be attempted safely on any average soil 

 here, at intervals : that a frequent repetition was at 

 the risk of sending the place to sticks, and the pro- 

 prietor's future prospects to the resting-place of 

 a as ! so many a fair hope ! As to whether I am right 

 or wrong in saying that it was found positively 

 necessary to add nitrogen liberally, question Messrs. 

 Elphinstono, W. Smith, W. McKenzie, and the hosts 

 of other in the past successful planters in Dimbula 

 and Uikoya as to the nature of the manure.- they 

 used in producing crop after crop without injuiy to 

 the coftee— crops that they wo'dd otiVl be aliening 

 were it not for leaf-diseace, and in a lesser degree 

 for adverse season and grub. Ask Mr. W. Cameron 

 how, and in spite of the fine soil, it would have 

 been with the splendid succession of crops of 

 10 and 12 cwt. per acre throughout his re- 

 gime on Galiha, or with the estate itrclf 

 had he stuck to pHin bonesor mineral manures only, or 

 principally ! Call on the shades of poor Lawrence 

 Carey for an explanation of his indisputably gp-at suc- 

 cess in manuring ! And not to leave the richest section 

 of the island in point of soil unnoticed, perhaps the 

 manager of the Uva t'ompauy will kindly enlighle" us 

 as to the meaning of the many cart-loads of rich and, he 

 will not deny it, ux.nnsive cittle-duiig to be seen cirried 

 out occasionally on iiassing through Spring V;.lley. 

 Why a niHitoossary oui lay, with bones at present ■•otes. 



