FERTILIZERS. (By Agricola.)

North Otago Times, Volume XXVIII, Issue 2081, 3 January 1879, Page 1 (Supplement)

FERTILIZERS. (By Agricola.)

Pakt 111. Previous to entering on the subjec' proper of the present paper (bone manure*) it will be necessary to correct one at least of the misprints, which tended to alter the sense of the last paper treating on guanos. In estimating the quantity of ammonia present in guano — for 14 lbs. in every 700 lbs., read 14 lbs. in every 100, which makes a very considerable difference. The other bull? I pa»s over as they do not materially effect the seme of the paper. Bone Manures. — This is the general name applied to that group of substances, into the composion of which phosphate of lime enters largely, including bone earth or roasted bone?, bone meal or ground bones, soluble phosphates or bones dissolved in sulphuric acid, and superphosphate or a preperation of fossil phosphate of lime. As showing the importance of the liberal u«e of one at least of the above substances, I will quote a few figures in connection with d.iiry husbandry, which will I believe more fully bear out my meaning than atty argument* [ can use : thus the average qualify <>f phosphate of lime pr pent in milk is about 2\ lbs. of every 1,000, or to ute more i'.telligihle language, every 10 gallons of milk contains about 3£ ounces of |>ure phosphate of lime, or eq-ial to 7 onces of drie * bone*, this is in alilitioo to the quility require*! to build up the finm- of rue row, repairs w iste &c. N.»w pntvi led the cow yield* 750 gallons <i! milk in a venr, or rather over 2 gallons lier diem, we have the soil reduced by the infraction ol something like nu equivalent to 40 M>B. of bone du-t during the course if the year, aivi when to 'his \* a Me I the •he quantity which goes to h.iil I up tne young or fat beasts s -Id ; it is cvi lent 'hut the s> railed improvrinent to the laud by grnzing, is in ■ > far a« phosphate* <ire coin-erne I rather a doubtful benefit, that this is not the'trv is clearly proved, by the experience of the greatest cheese nuking ami dairying county in E inland-— Cheshire— where the old perm incut pa*Jtures were ufier a long course of grnz ng almost exhausted, an I were only renovated by the liberal me >f bone ilust. Now if we >nr» from the product* to the auiinil. we rind the pr<>p irtion of bme present •■ome-n-hat hi follow*, in the borne 1-B'b. of the live wight, in the xheep (old mtrino) about as much or equul to ]-sth. of the Jen. l weight ; these figure* will 1 trust * rye to convey an ilei of the greit chunges brought about in the composition it ttie soil, by what the raajoiity of farmers consider a state of' rent or rt'Ciui'iug uif Innd for a I'resh effort at cmptiing, while in reality it is onl\ changing the proInot crovvn from *o £ »ill now ntiortlv describe the mode of preparations and tiifferencv in theempositinn of t\ c vnrioiiK substances embraced under the leading of bine uunures. The I tri-ha«ic phosphate of lime of the agriculiuiitt is composed of about 48| per ■ent. of phosphoric acid to 51$ ol lime, >r, roughly, half phosphoric acid and halt lime, and as rather more than half the I >v light ol dried bones is made up of phosphate ot lime, it is evident that rather over one fourth part by weight of bones i*i formed ot lime rather It ss than another tourth is made up of phosphoric acid, gelatine forming about one third, the balance being made up of various salts in small quantities. 'I he first bone manure to which I would divert attention, is bone earth prepared by calcining or burning the bones in an open fira, which has the effect of driving off the organic matter, such as gelatine &c, and reducing the weight by ahout onehalf ; the residue being almost pure phosphate of lime, this substance was largely used as a fertiliser, being rich in phosphoric ncid, but it is now pretty clearly proved that the benefit the soil derives from a ton of bone dust is much greater than from half a ton of bone earth, each being the product from an equal quantity nf boues. It will be unnecessary to day more about this form of bone manure, as it is evidently not a profitably manner ol treating the substance. Passing on to the next in order we have bone meal, called aiso hone dust or ground b >nes : for ennveuience I will take this substance along with the dissolved bones or soluble phosphite/, ns the first sta<ze of preparation are nlentic.il in each, while in compo-ition they are Bnme with the exception of t'le ncid, added to the latter to dUs >lye the phosphate. The u»U'il process adopted i i (he preparatio <of these substancts is first to crush the boms to a convenient mz* lor jiiudmg; lifter grmdin » they are either ••old as bone dust, or disaoled in ah . t i »lf their weight ol sulph nic act I fret U diluted with water, in from two to thie< I .iv a t lie process is so far completed, that the bones are dissolved or reduced to P'k«te, or to explain fuller, the clnnga which h>»« taken place the phnphtte of li ue h'H been altered from umolu'ile t « soluble, in which latter *tafe it can be wa-ted out with the rain, and m-tre rea)il> taken up by the plant. Tni-< pi»te can be ipplied either by dr\ing it ui> with char■oal, or fine so I, and <lrilluu in with the root crop, or hit-rowing in with .■rain, or it may lie diluted with 50 times its hulk of water, and applied at a top i r «Hisi:ig to any crop !>•• im-ans of a water■art. Numberless exptrimen'i have been made, the re-ult of which q . to -.'in v— int. 'he urcat value of bone as a fertilizer, and sec "xl, the beneficial action, which the a II tia< on the'bones. I will quote one of the •nanv given by Jnhmton, which clearly proves that the ici I plnva an iiuportuut part, it is as follows : 16 bi^hels of bone dust(undissnlve(l) ncr acre, give 10 tout 3 ewf ol turnips, v\hi!e on the same land 2 bushels of di-soheil bones or anluhle phosphates, gnve ns hL'h an 11 tons 15 L-wt and 4 buiht-N, aUo ilN.sidve'l nave 14i tons per acre; 'loobtlc.->s the tirst application would resemble the results attending the liming of a farm »iz. , exercise a beneficial result for a number of years, but in a i olnnv such as this few cm affor.l to lay •ut money with the prospect of a benefit n the far future, when there is a prospect of a greater and more speedy return within a few month* 1 . \\ ith the view to test the qualify of the bone inanine obtainable from a well known source of supply in the neighborhood (I r< fer to the steamed bones sold by the Meat Preserving Co. at Kxkanui) I procured a sample, mid through the kind<ies« of a professional gentleman in town, who placed bis laboratory at my disposal for i few wuiojpj I wu cutttoi to mike

>in approximate anal vis, using the process of the late Professor Pr>nnv. of Glssi!o», fur the es'imation of nolnhle and unsoluhle phosphates. I entered on the i»r>ce«x vi ir li a prejudice agiiinst the s'uff for douhtUsstr ha<l a vile smell, and looked as if it rniniKine the better of the an I exposure to wind and rain it hivl undergone, but a't<T dissolving and precipifating the phosphate*, inj opinion like the thermometer on a warm day began to rii" and finally on the process being completed aud the resultant weighted, I registered a mental resolution to invest the tirst surplus cash in my possession in a few tons of the stuff. The results exceeded my expectations as without any preliminary drying, and simply breaking the bone* roughly with a hammer previous to dissolving in the acid, I obtained 40 per cent of total phosphates, and on estimating the soluble I found 7i per cent, thus showing 32} of insoluble, which could be dissolved out with acid previous to applying it to the soil. When it is recollected that great quantities of bone dust sold in the Home country only contains about 32 per cent of phosphates nyrninst 40 per cent obtained from the Kakanui <-ample, and as the manufactu»t ol sulphuric acid ha* I believe been commenced in the colony, and bids fair at no distant date to figure largely as an article of export, I believe the time is not far distant if not at han'l, when the manufieture of pure hone manur- csn with profit be added to the too short list of local in* 'lu*tries I will now glance shortly at the List livision of the subject in which I intend trtatinir, viz. superphos;)h «te<, these m iy by minuf «cturi <l either from hone earth lief/ire described, or fr<nn the miner*' ><p •!»«>, which c'xttuini « lar^e percent* u< of ph'isimate of lime, when prepared from mniernl or fo«s|i phosphate the «uh»tin«*e i« to n «-oar«e p-nvdi-r, after which «tni»e t lie priice«u of t irepar!tti«»n «»he'her fro'ii hitne «ar'h or from minerals i« the same viz., dissolving with acid when a q la'itity of the lime fi!N to the htttom; with the nutp'inr of the acid forini nir plu-ter of 'an«, K'nvi'itr the rcu ainder of th lime in the liq'iid wirli the phoxpfmte, whi *h is drawn off and evaporated todryne-w, fo'ining a whi'e powder known as the nci«l or •our superphosphate of comm;'ce, the great drawback attending the appli> a ation of the •nperphosph'ite i« the variable n »f lire of its composition, one simple b in .' rich and prod-icing splendid crops «vhil«* nnitthercan be sj made as to be nearly mele»s\ In concluding this rough sketch of bone mtnures I can only a Id t'mt to my min-l tlnri- is no clh^s of fertilizers <v|iich are likely to uive equal sittsfaction to the firmer, or to impiove an I iiMiutiin the f nility of the soil a« those above described when they are hnn«-s.'lv preptred. In the next issue I intend bringing trw pipers to n close — treati'i>; on liming and s one of the minor ferriliz t».