LIMING.

Otago Witness, Issue 1851, 29 January 1902, Page 6

LI MI NG .

An aveiage yield of 24 tons of potatoes pei acre, which* was gatiK-ted la-t season on the Kail of Kosebery'v home f.nm, Dilmeny. is altogether phenomenal, bung about twice the quantity that in ordinary (Scottish expeiiences would be accounted a very good crop indeed. The soil of Dalmeny, .ts m several other parts of the favoured Lothians, is pecuhaily adapted to the potato, but last season's yield, giov, n \>iih tlie direct aid of ground caustic lime and aitificial manures oniy. seems to suipa^s all former ieu>rds. The inamni.il expei unents earned out in connect ion with the nnmeious agricultui.il college - and schools in Great Br.tam. as well as .it ihe pi (-mi- 1 station at RatlianiiUd. have been the me ins of effect ing economy in the dual sense of reducing expenditure and incieaslrg jjioduction. " N"ot only have the lessons denved fiom the trials- shown farmers the futility of excessive and indiscriminate m mining" (declares the Fie'di, "but tliey hive been likewise efficacious m enhancing the genci.il resu'ts accruing from the u«e of aitilicial feitihsers-. In shirt, the fact has been clearly established that intelligent rather than heavy manuring effects the largest and mo«t profitable leturn? — by intelligent manuring, of toni.-e, being meant the application only of those --übstaiices m their proper proportions and <juantit.es which a study of the soil and ciops shows t> be lequiied to restore or preseive the correct and chemical b.tlance. One jiromi nent lesson of extensive and repeated held experiments, has been the d s> ouragement of heavy mainning at long inteivals the superior effect and economy of giv.ng smaller quantities at short intervals — per haps to each < rop — having been diMimtly enipli i-ised. " In tegaid to no m.itcuai has th's truth been more forcibly substantiated than with Inn*, and in this rcsp»ct the Ddhneiiy exjjei inients and practicts aie di 1--tuictly demonstrative and conclusive, for they have .shown that he.ivy die-sings of lime as applied until recently by the inajoniy of S(otti-h fainicis, once in a long peiiud of yeais. h.id a most prejudicial effect on tlie liiinfjiiig and other advantageous -Oil organisms, whereas a mii.J! annual or biennial dief-Mmr of around (austic lime on the sui face 'oil w is of great benefit to ilmsp s O il organism- and consequently >•!.-() to the ciop^. I'lie pecuhuiity of the Djlmenv ovper. ments In-, m the piiiicipie upon which they aip condiKteil, which is claimed to d.ffei mbbtantially from th't commonly pursued The guiding principle in the i e experiments has from the outlet b»>en that which is gradually making itself known as the new soil science. In othei woid-, tlie tvpenmenttr.s have pioceeded on the u s-uwpM<in — now uriiveisaily a<cepted as coned — that the feitility of the soil is dependent upon the presence and activity of bacterial life, and that no matter how lavishly manuie is applied the absence or suspended action of tlie nifi living organisms cannot be atoiipd foi. The foil win. h is not occupied by s-jil baeten.i they hold to be necessarily infertile. Starling with these axlvauced theories ai tlum umdiiui lulM,

therefore, Messrs Hunter and Drysdale have conducted their experiments upon a new Kisis, inasmuch as they have pursued the indirect but economical method of manuring to piomote the increase and activity of the nitiifying organisms. It -would be be difiiLiilt to say how far this line of procedure has led the verdicts away fiom -what has been obtained at other stations, or what the oidmary method of expeumentation would have produced upon the same land, but it is pretty safe to assume, having regard to the vital pait played in the fertilising of the soil by soil bacteua, that the system which takes due cognisance of their picsence and woik is the one likely to produce the most economical results.

One of the most effective and valuable sections of the Dalmeny scheme of experimentation is that directed to the d scoveiy of a remedy or cure for the devastating turnip disease familiarly known as "finger and toe." The circum>tances under which the nulls were made were admuab'y fitted ti test the efficacy of the means employed, and the severity of the test renders all the more encoui aging the very remarkable measure of success attained. Three successive ciops of turnips, every one of which L. d bpen mactieally or wholly ruined by the diseased h.id been taken off the land previous to the experimental crop, so that the land was full of the <-peds of d seise. Lime was the agent employed, but at iirst a difficulty presented itself in that a drcss"n? sufficie-it to check the disease would be fatal to the soil organism*, the lattp- belli.; quite unable to withs-tai d the effe-ts o\ say, four tons of cau>tu: lime to the ace, while a small dressing would have little effect upon the disease germs. The course ultim itely resolved upon was to apply one ton per acre of hot ground lime in the autumn before the land was ploughed, and another ton of the smie substance wli >n ih° land ■s is !_Miihbf-d !)■ fine <. D f.l'iia .v thp sjniiu;. tins dressing be.ng followid with a mixliue of Bc w t kaniir, 4i;wt utidi--!;(ihed phosphatic nianuie, and levvt sulphate of ammonia in the dull at the time of panting. This treatment has- proved very effective in combating the d sease, as even under the *{"eie condituuis imposed the yield of crops i bi .uned '"rom the tieateel '-.yd weiglied 17 io>is ppr (Hi-p, vi which tiii'v 4 per c lit. of the roots weic i.i the --lii;hfe-.t d'gre efiPLted by the d s ac-e Compa el w t'l tlrs gratifying result, the unlicated plocs maiirlestcfl a s;;d sp'jf lacle. the io<>ts <„-. them being so thoroughly di-ctscd as to be scaicely worth removing. On 1 1 jo .strength of the evidence r .nth ,-.• 1 t Diimeny. similar tieitment had h r cn fi '.I in ordinaiy field cultuie im otltfi- di-tn Is. and it is stated that rovupU-ro s;i o. •<■ insulted m each case. It s 1 v.iy mpot a t. to note that tlie app'ic it ion "f T- w (. ic 1 inie of kaimt is consider, d int il i~> (h 1 success of this method of ]>i v^ntt n. »tid ecjually so to mark the a^odT.c 1 of ds solved phosphates. TliPre i- nj moic popular and effective hump mantiie tlun superphosphate, but it ln.s m Scotland for soinc time been suspected of an objectionable tendency to favour the dt-velopmrnt ot finder and toe disease, and th' Dalmeny observations have conlii Hied tl'i> blowing h,'l'ci.

Foi most «(nK line in '■ome ftim is need'ul in older to pie-.ervf> llum in a heilthv and piodu'.tive si.ite by npuiuilising a< i inpul.it ions of acids ,iiid otheiwi«e p-'o-molinji and facilitating the activity of the mtiifviii^ organism-, the va'ue of wlio^e op- rations i-. now generally recognised. In Scof laiid. until cjuite lecently. it w.k ihe pi act lie of those who woiv sufficiently ob••"ivant to peifci\*e the adv.int.ijjes of ]i»)jn_; to .ipply 'm^e diessjngs of tin ce to vik ton-- ju'i a<ie peilups on< c in a (It-uirh, while in some cn--es the laud was thought 1o hive been satisfied .is re^.u.ls lime if it ieceivp'l one good dressing in a 19-ye.tr s >' lease All tlu.s has bepn (handed, if not enliielv in practice, .it least a» f.ir as intelligent inti'i pietation of well defined pr.u-l.cai results ,ue (oncerned LirtfP ;ipplic.-cJtion-of lime Inve not only been --houn to lie wakeful, but in some de_ r ice haimful. in th.it )he excessive quantity* defeat the pi unary objects of tlie application. While the appl'i-atinn of l.u^e" diessiujrx of lime is uiiqiK'siimiably to be deprecated it will be perceived that frequent applications in srm!l quantities lnvc the advantage of promoting .it sliort inteivals renewed activity of dcs l.iblc «ml oi For in-tance. in man y p.nts of Scotland it is now ,idvi.sed ih.il lime (ground) should be applied ye.nly in quantities of sewc w I per acie. which c ounspl. it is but neht t^ -.ay. i> ba«ed on .ulii.il fiHil result< The D.ilmeuy expeunient-. have been the «ouici' and chief exponent-; of this lnnocent-'ookinif method of lup inc. .iiid whatever one may l»e d'?po c erl to think of its possibilities it is undeniable ill it, nii> ism i(1 by the ri Mi'ts produced then. Us mewl- n e worthy of the clope&t con-t'dprntion As can be reulily understood, applied on the D.ilmeny s>\*-teiu, the ltine <.( until ites the nitiihin^ oig.uiisms. and thus induettly conduces to enhance the feitihtv of the" --oil. At Dalmenv, as a matter of fjet, the whole of two large farms is ti e.t t erl as an expenment.il station, the system that grave the best reMi't* on th? experiment. i! j^rour.ds being earned out all over the farms. There had been many who had sneered at these experiments, but that fact h.id not .iff"it.-"d the lOMi't*. The expsiiment'M> h«-ld iiinily by the opinions whnh tlie} h.id foiir.d to be coirecl; but, while tliPv h-'.d firmly by the-e npmioii«, they avo'ded tlie v.mv .ippe.n ui<e of foic'n^ their opinion-- on others. A-> Loid Ro<-e-Ijf-iv's mnidge-r of the piopuity (Mr Urysdalt) explciim-il to a L.rge assemblage of f.nmt'is on a visit of inspection: "They sought to show \isi(.oi> wh.ir was- much Itetc-r th. in official figiiic-s and report 17 — namely, <>ops Midi a-, he was safe to i-ay. they would not lincl tlip better of 'n any ]).ut ot the count iv. They were at all limes ready to show interested a&rnculiui isf? over the experimental gi'ounds and the farms, and to give nny information that was in their power to give. They aimed at showing how to- farm well ,md piofitab'y. and they did not endeavour to bhow", as some noted experimenters had done, that 10 tons of faimyaid manure per acie gave better result*, than 20 tons; Ikat^gui^e has.

the best fond of all for feeding sheep on £_ t>i" that jou could grow white crops cont.nuously on the sams laud for 50 years without prorit. '

Accoidmg to the experiments and testa conducted by Lawes and Gilbeit, there is an annual lo^s of lime from the soil per impciial acre of about scwt, removed b3" crcp-s and drainage w ater ; the 4cwt to 6c\vt annual applications of ground caustic lime as practised at Dalmeny would, therefore, compensate for depletion of lime in this ■Wiiy. while stimulating afresh every season the action of the beneficial soil organisms and neutralising hurtful ac : d'ty. But so many nnd varied are the peculiarities and

conditions of soils, that di-essings of lime, -whether ground caustic or slaked; must vary in quantity in order to secure adequate results. In reference to the prefeience now bestowed in Scotland on the use of ground " hot " lime, a farmer wrote as follows to an eminent authority :— " I notice that farmer-, are recommended to apply scwt to 6cwt per acre of ground hob lime to land deficient in lime. Why is this belter than 1 ton or -2tons of slaked lime per acre? I have never seen the scientific explanation of the advantage of small quantities of ground lime. It can hardly bp in a. finer powder, I imagine, than slaked:' lime." The following was the reply: — '" Ground hot lime is lime ; slaked lime is piactical'.y calcium hydtate, and these two materials ai-e chemically different both as regards composition and action. These are sufficient reasons for prefeiring the former to the latter. It has been proved after years of experiment that a dressing of 1 ton to 2 tons per acie is. distinctly disadvantageous, and that the smaller quantity — which rapidly becomes carbonate, a most important and until leeent'y disregaidtd feature — supplies all that is lCijuirerl for the advantageous soil orrrmisms. OnJy when certain life is lfjuucd f.i bo cifslroyed is a difssmg of 2 f i 'i? of "liip.r— , slal. fd or unslaked — iea-on -bl". and, v. i( h that exception, desliuH ion of life is Ihe? very antipodes of :at ; ..nal agrrcullure ; hence tiie leason f-u small dressings of lime, which are as rs-ent'-l .is muMI dressings of phosphates or pr>l«i>-ii or nitrogen."

The two "l-ojit -di.stuibm.; elcmrnis of a:;ri' Maiinil < \ peiimvnls Pie variation- m He thcr and in s-oil. T!t> f!i^uniiri; inilupn'-p of the weather is tlip «,•).■ ,■ i<=ss tmnn: t..ncc. and is got tid <■" In- ihn> u-iting tha evparimpnt« in diffpr- ° k ti,-iiKls, but c-specially by repeating li. ' f mi: mi iis dui'iis! sfvci.il successive \ !=. .i.'d nolini; lur.v- the vniying meteoroT■ g rat ( i "<]i(.ioi's uTcL Ilk" 1 ies.ulls. r J\> cl niiiiate iho d" turbine; influences induced b,- \aiK>--if>n< of soil tlie experiment must be rrpcaicd again and again on a variety of soils, ,'inj this ■-•lic'n'd he done, not only in any one year, but aNo during a series of mis It in the end ye Und tha! tlia ..(fri," 1 re-uUs of one j"e««"r are confjiincd by tlie expeiiences of the next, and espec'iilly if suni'ar remits are got dining several Aears, then there can be no doubt thct we are justified in concluding that we have gqfc hold of a fact that is capable of general application. The Dalmenv experiments alone v. ould not h.ive eventuated in the v\ id»iv 's[ue-'(l sy.slem now prevailing in S. ot' md of sm-ill and frequent dressings cf giound hot lime m pieferenee to heavy applications at long inteivals, but thab mimeious evpeiienced and well-infoimecl< Scottish farmers recognisfd the truth of the doctrine that a soil to be fertile mil 'ft be germ-occupied — that is, a sterile soil is an infertile soil, and that the manures applied to soils which were previously supposed to directly nouiish the plants are in> ic-ality the foods and breeding necessities for soil orgairsms, and it is these bacterral bodies which conveit the added materials into soluble and useful compounds for plank absorption. They readi'y comprehended that heavy applications, of lime destroyed or mipiirfd the action of the useful soil organisms, and the system of small bub fiequent dre.sMngs erf ground lime has been veiy generally adopted.