ON THE LAND

Taranaki Daily News, 26 April 1930, Page 32 (Supplement)

ON THE LAND

PHOSPHATES ANO LIFE. *■ • . / FOOD FOR THE SOIL. IMPORTANCE OF USE. Mr. P. H. Cutting, F.1.C., writing in the Fertiliser Journal, gays: Life, as we know it, without phosphates would be impossible. About one half of every .bone in ones body is phosphate. Phosphate circulates in the blood and supplies the muscles, nerves and brain with vital energy. Invention, art, literature, in short, all the products of thought and work, depend on an adequate supply of phosphates. Thia supply comes from our daily food, whether animal or vegetable; in the first instance vegetable matter. We can easily understand, therefore, how vitally necessary it is that the soil producing the basic elements of life must contain plenty of phosphates. Docs it? Except in very uncommon soil formations it does not. Natural supplies of phosphate, even iff virgin • soils, are very meagre. They are quickly exhausted by cultivation and must be replaced artificially if fertility is to be maintained. Fortunately for mankind nature has concentrated in certain parts of the world—notably in North Africa, North America and some islands in the Pacific —enormous deposits of phosphate, the mineralised remains of animal life in past ages of the worlds history. It can be truly said that, but for these deposits and their discovery by man, the human 'race would to.-day be in a very bad way indeed. As it is, thanks to this provision of nature, supplies of phosphate are abundant and in no danger of early, exhaustion. Discoveries of further' deposits occur- periodically and will probably continue to be made, as the result of continuous investigation of nature’s mineral secrets. To Liebig in Germany, and to Lawes

in England belongs the credit for discovering- a process by which mineral phoisphatCG are made soluble in water and immediately fit for absorption by plants. These pioneers found that the mixing of a ton of ground phosphate with a ton of sulphuric acid produced nearly two tons of a readily-soluble

fertiliser, which was called superphosphate, ' reaching to-day the very, large total of about 1-1 million tons. The particular merit of water-soluble phosphate Ls that, through the action of rain-water, it becomes distributed through the upp’er eoil in a very per-

fect manner, such as obviously cannot be obtained for any solid powder however finely ground or carefully prepared and applied. The dissolved phosphates quickly combine with other substances in the soil, and, while remaining available to the plant, are no longer eoluble in water and cannot be washed away and lost. For thorough distribution and quick results, water-soluble phosphates stand pre-eminent over all insoluble forms.

The Fertilisers and Feeding Stuffs Act, 1926, prescribes as the legal warranty the percentage of phosphoric acid, instead of the percentage of. phosphates previously required. This simply implies a statement which must be made by vendors to show the farmer the grade of material he is buying. It in no way implies that an acid is being added to the soil. In fact, basic slag and ground mineral phosphate, both of which must be sold on a guarantee of so much phosphoric acid, are, in one case, alkaline, and in the 1 other either slightly alkaline or neutral. The phosphates in both are all insoluble in water. In the case of water-soluble phosphate the sulphuric acid used in its preparation is not", as might fie supposed, deposited in th-' soil as acid. A good deal of error aiid misrepresentation has arisen on this point. What happens is that the whole' of this acid combines in the process of>• manufacture with the insoluble matter hi the raw phosphate to form completely new chemical substances. Principal among these is sulphate of lime, a neutral salt, and itself of distinct fertilising value. It has been definitely and abundantly proved, by trials during many years in this country, on the Continent and in U.S.A., that superphosphate Moes- not cause soil acidity, but in many .cases actually-reduces it. There should be no; room for doubt or misrepresentation on this point. That soil acidity docs exist/ particularly in lime-poor soils, is unfortunately true, but it is due to other causes, and can only be adequately corrected by occasional dressings of lime; and, where necessary, by prosier drainage.

When' choosing from any of the complete fertilisers marketed by reputable vendors, the farmer should make sure that his choice contains a reasonably good proportion of water-soluble phosphates. Most of the nitrogen and practically all the potash will be readily soluble,- and the phosphate must be equally- available to-give a manurial balance; and for the plant to. find all the nutrimeent it requires from the start. . SHEEP FLY DRESSINGS. EXPERIMENTS WITH OILS. Though many types of dressings are commonly used for the treatment of cutaneous myiasis of sheep, which is caused by infestation with sheep blowfly maggots, oily dressings are the moist common, as oil possesses two valuable properties —it penetrates the wool well,, and it persists there. The objects of experiments carried out at the Nyngan experimental farm in New South Wales, recently, was to test various oils, both alone and with the addition of colouring matters, by applying them to the wool and skin of sheep to determine their penetrating value, adhesiveness and durability in the wool, and thus to determine the most suitable base for a blowfly dressing, Four tests were carried out. I

Reporting on these tests, Mr. C. R. Mulhearn, veterinary research officer for the Council for Scientific and Industrial Research, stated that the oils which proved to be most suitable are olive oil, fish oil, herring oil, whale oil, neatsfoot oil, and cotton-seed oil. Olivo, oil ig too expensive to be used on a large scale, and so must be discarded. Fish oil, herring oil and whale oil are of about equal value. Fish oil and herring oil have the disadvantage of being slightly - irritant to the skin of the back, though they showed no signs of irritation on the crutch. Whale oil may

be only very slightly irritant to the skin of the back, and although it gives better results as a durable and persisting oil on the back, it does not give such good results on the crutch as fish or herring oil, but it does not penetrate so well, oils. Neatsfoot oil is quite a suitable oil, but it does not penetrate so well, npr is it quite, so durable as the above oils. Cotton-seed oil is next, but being a thicker oil it does not penetrate so well nor is it quite so durable as the other oils mentioned. ’ ■

Of the remaining oils none is very suitable as a base for a fly dressing, each having some serious disadvantage. The mineral oils generally, and particularly the fines ones, are too irritating and severe on the skin of the sheep, whereas the thicker oils cause matting of th? wool. In all cases it has been an outstanding feature that where there has been irritation it has been more severe on th? back than the crutch, while in some cases, although there was a severe irritation on the back, the skin of the crutch remained normal. Similarly the oils have been more persistent and durable on the back than on the crutch. This is probably explained by the fact that the oils are not able to escape so easily from the back as the crutch. FOR JUDGES AND EXHIBITORS. HANDY GUIDE ISSUED. A publication that, will prove of particular interest and value to stock breeders has just been issued by the New Zealand Friesian Association, in the form of adjudges’ and exhibitors' guide. As its title indicates, it has been published primarily to give judges (especially the beginners), exhibitors, and the public a better, understanding of shows and showmanship. So far as it is known it is the first work of its kind to be published in New Zealand and the material it contains is authoritative, as every care has been taken, to get the opinions of highly successful and practical men of long experience. Special extracts have also been ■ made from the works of world-recognised authorities. It is a most informative booklet. In addition to detailing the methods adopted in judging dairy cattle, and pointing out the most common faults, it discusses in special articles such matters as breeding, preparation of show stock, the value of skim milk and the food value of milk, and a dozen and one little points that will prove extremely useful to the progressive breeder. In the foreword, a tribute-/is paid to the work of Mr. J. P. Kalaugher, secretary to the Friesian Association, who first conceived the idea of compiling the publication.