GROUND CAUSTIC LIMP.

Otago Witness, Issue 2471, 24 July 1901, Page 6

GROUND CAUSTIC LIMP.

The Qeld expeiiment* inaugurated some years ago in connection ■« ith the Durham College of Saence. and which art; to be duplicated under the au-pices of the Board of Agriculture during the next few years, U different cqienmerital stations in Great Uritaiu, have shown year after ypar that the applkacion of a 4-ton per acre dressing of j CdU^tit- lime is a most uuprofitab'e investment, -whereas the application of 10<rw t ground lime per acre, >v alternate year.?, had resulted in the plot so treated producing '•the highest aggregate of all."' "Thi« undischarged debt of the heavier dressing."' Professor Middleton says, "is, a rnelaneho.y •embiem of the burden too often hud upon poor land by unpractical improvers.' On the other hand, he points out that "where lime was used in a piactical manner (as in plot 8, which was dressed with 7c\st mineral superphosphate and lOcwt ground caustic lime per acre, in alternate years) there is no heavy debt hanging over the p.ot. The application has. it is true, hardly paid so far. but the herbage on the plot has now a fine vigorous look that shows that a direct profit w ill soon be forthcoming. The character of plot 8 is pretty well indicated by the deep short-legged sheep feeding on it. There is a huimuia which is lacking in those fed upon plot 5 (7cwt superphosphate in alternate years), where the same amount of superphosphate Avas used without lime." With regard to this quotation, it would seem that some mist ike has been made somewhere, for Dr Somerville, Dr Middleton's predscessor, m his article on the expeiiments, in the December volume of the journal of the Board of Agriculture, says of this same plot 8, "This is a plot in which the interest increases each season, and this year it merits Fpecial notice, as it has produced the greatest aggregate oi all." Probably the explanation of this apparent discrepancy is that the diagram repiesents the accumulated live weight increase of the last three years of the sheep grazed, and Professor Mi'ddleton in his none refers, not to the last year's live weight increase, but to .the accumulated live weight mciease of the last three yeors. The all-important uses served by carbonate of lime, the form to which caustic lime is rapidly converted after being mixed with the soil", in feeding and stimulating the action of the nitrifying and other advontageous ,=oil germs, are well known to farmers in the home country 'who have studied the scientific principles underlying successful agiicultural practices. They have kept abreast of the most advanced scientists of the time, and know full well hat it is better to apply lime in smaller quantities, and oftener. than to pursue the that it is better to apply lime in smaller at a time, in the hope that they will last for a number of years. Furthermore, they have ascertained that caustic lime, finely ground and immediately incorporated with the soil, if even in small quantity, is much more powerful and effective than the very much larger drewng of slaked lime ordiiuiily given. A small dressing of caustic lime properly incorporated with the soil is rapidly converted into the cai'bonate form, and it is this speedy carbonisation in the M)il that has suggested the growing practice of frequent liming in moderate quantity, for a heavy dressing of caustic lime '•will almost invariably do harm bykilling off the germs of nitrification. In Great Britain nowadays, the quantity of caustic lime applied to laud under preparation for turnips ranges from scwt to lOcwt per acre, according to density of soil and other conditions, but when danger is apprehended from finger-and-toe attack, much heavier dressings — varying from one to two tons per acre — must be applied. It is recommended by experienced farmers in Scotland that in the case of heavy land, a ton of caustic Hint jjer acre should, kw

worked ii.to the -oil b\ mean"! of a grubber 01 cultivator, arc! that" again in spunglime, three weeks at le.i-t bci- re the appluauoii of aitificial mamnei or seeding for the civp, another ton of the lime should be applied. This treatment N alleged to have killed out the finger-aiid toe fungus in soils infected. Since the system of applying small dressings of giound emetic lime became general in Scotland, seme of tlie grinders have greatly induced the quality, and m consequence f.nmers *-o warned by the agriculluifil journals, against the purchase of this manure, unless nndci a guarantee that ife contains 70 pc; cent, of ox'de of calcium. Tn this connection the North Biitish Agriculturist his Ihe following: — '"Professor iliddleton'i diagrams, and figures relative to> expeiiments in liming, together with his dictum as to the lOcwt per acre dressing of ground lima in alternate years being the only 'practical m-xnner' in which lune may be piofit-ibly applied, remind us that this year a very luge quantity of lime is being applied in th it 'piactici'l manner' in the profe^soi's native comity of Rot^-shire, ay here* h.s father and iv>aiiy other relatives have more than a local repuuiton as practical demon«nator& of the best agricultural principles. Messrs John (.'ran and Co. , who are 'the predominant partners' in th» manure arcl cake trade in the northern countie>, ha-ve this year experienced an unprecedented demand for ground lime, most of t\ hich was ordered from Ro^s-shire. Messrs Cran ar.d Co. were getting their lime from Keith Lime Woiks, where the demand for ground lime has been so heavy this, year that they have been unable to fulfil all the orders sent into them. The> Keith lime Wc>s found to analyse 70 percent, oxide of calcirm, which wa« very satisfactory. Some other Ross farmers, however — 'Mr Ross, of Tan el, was one of them — obtained a supply of ground lime through another agency, from another set, of lime woik=s, and their experience on the subject may serve to point a moral or adorn a tale. Knowing that the stuff was suspiciously cheap, that ground lime was liable to be heavily adulterated through -ansciupulous grinders alloy, mg 'danders' ,v.d other lubbVh to go through the mill, Mr Ross. v,-iih characteristic cuteno, stipulated with the local agent ilnovgh whom he got the stuff thai, for every percentage of odde of taleium which the {.'round Jinie showed muter 70 per cent., there should be a deduction of 1£ per cent, in the price. On the stuff being delivered, it wr-= ioiind on analysis th.it it only showed 35 per rent, ox'de of calcium, so that, according fo tlie terms of tl>e p.grremenfc which b<- hid b?en cute enough to make. Mi Ross found that the pnce"he would have to pay for ths stuff was undtr vanishing point. Whether the oih-.r fanners m h's neighbourhood who gut the « inie stuff, through the same -asjelic-y, had. t,"ken ciual c:ive to protect/ themselves we do not know, but cerrain ifc is that there i-. no lßjurjrc so liable to adulteration .h g round lime, and in every case, thcr?£ore, it .should be bought with a guai.mtee of at least 70 per cent, oxide of ci'lcium. ai d the stuff should be tested by anahfis to lvphe sure that it comes up to the guarantee."'