FOOD FOR THE SOIL.

New Zealand Herald, Volume LXVII, Issue 20593, 18 June 1930, Page 18

FOOD FOR THE SOIL.

FERTILISERS IN AUSTRALIA.

TARIFF BOARD'S REPORT.

IMPORTANCE OF PHOSPHATE

One of (lie most comprehensive ami Important reviews of tho present and futuro portions of artifwial fertilisers in print is that issued by the Commonwealth of -Australia's Tariff Board. It is thoroughly practical; it is absolutely impartial, aud it deals with all classes of fertilisers in a thorough and completo manner. Naturally, it deals largely with Australian conditions, but no one can read the ovidenco given without realising that much of tlio information given can bo made to apply to New Zealand.

In tho introduction to tlio report it is stated that the paid-up capital and .reserves of companies engaged in tlio manufacture of fertilisers in Australia exceeds £6,000,000, that direct employees in tho industry number 2500, while indirect employment is given to thousands in the discharging of approximately 700,000 tons of phosphate, rock and sulphur annually, and in tho transport of over 1,000.000 tons of fertilisers to farmers throughout tho Commonwealth.

The Commercial Aspect

The commercial and manufacturing side of the fertiliser industry is, of course, of great importance to both Australia and New Zealand, and will further increase as years go by, but. it is the effect of fertilisers on the various branches of agriculture that gives the greatest results, though, from a national point of view, the two aspects should be given together. In dealing with phosphatic fertilisers, the report says:—"lt is almost imposiiblo to exaggerate tho importance of superphosphate to Australia. Though tho history of the use of superphosphate on the wheat lands reads like a romance, the result, following the top-dressing of pastures with this fertiliser, is no less remarkable. It is generally recognised that the stock-carrying capacity in tho areas of reliable rainfall can bo doubled and trebled by application of superphosphate. Not only is this so, but the quality of the herbage may be greatly improved, and the very nature of the eoil altered."

The report goes into the question of raw materials, and shows that, as in New Zealand, the great source of supplies of phosphate is Nauru and Ocean Islands. It deals fully with the attitude of tho British Phosphate Commissioners in their management of this supply, and pays a handsome tribute to their generosity in dealing with both countries. From figures given it appears that Australia now imports, through this source, over 500,000 tons, while lb obtains 91,344 tons from Morocco, and 96,688 tons from Makatia Island.

Supplies of Sulphur.

An important chapter of the report is that dealing with the importations of sulphur for the manufacture of sulphuric acid, and estimates the cost of this material at about 25 per cent, of the raw material used in the manufacture of superphosphate. It is obvious from this statement that sulphur is a very important J#ctor in our fertiliser problems, and it is by no means satisfactory to learn that the price of this product is rising, and unless further largo supplies are discovered in the world, it is likely to rise. Tho board, in dealing with iliis possibility, discusses other materials from which sulphuric acid can be obtained, and points out that in Australia zinc concentrates and pyrites,can be looked upon as possible sources of supply. Apparently the landed costs of sulphur in Australia has risen from £4 17s 9d in 1925-26 to £6 in 1928-29.

With the. view of cheapening the cost ©f sulphuric acid, and at the same time assisting Australian mining, a bounty amounting to £2 5s per ton on the sulphur equivalent from Australian minerals lias been granted, which has had the effect of reducing the price of superphosphate by 5s per ton, and encouraging the production of sulphuric acid from zinc concentrates to the equivalent of 25,500 tons of sulphur.

Another possible source of sulphuric acid dealt with by the board is pyrites. It is stated that when tho Lake George mine in New South Wales is connected by rail, pyritic ore will be delivered tit a price that will successfully compete with sulphur. At Mount Lyell, in Tasmania, and other places, there are largo deposits of pyrites. Experts say that after allowing for the bounty of £2 5s per ton allowed for sulphur obtained from Australian minerals, sulphuric acid can be produced at a cost lower than the cost of acid obtainable from brimstono sulphur.

Deposits in Auckland District.

Theso facts are of considerable interest to New Zealand farmers, and if the price of imported sulphur continues to rise ifc will certainly be desirable to examine our own resources of minerals likely to produce sulphuric acid. Fortunately them fire in New Zealand, at White Island, Jiotorua and Taupo, well-known deposits of raw sulphur, and new deposits may bo found 'by boring. Thero aro also on tho Auckland goldfields large deposits of pyrites. If, as is suggested in the report of the Thames School of Mines, there'is a possibility of the low-grade reefs and metalliferous lodes of the northern goldfields being worked on a large scale, tho possibility of utilising their pyritic contents for the production of sulphuric acid should be taken into account. Hitherto this mineral has been a trouble and an expense, when working for gold and silver; if it can be profitably used it. would make a considerable difference ♦ o 11 10 economical working of auriferous iniil argentiferous deposits. Tho Australian tariff J'oard declares that if is worth while paving even more for sulphuric acid pioduced by Australian miners from Australian minerals than for that obtained trom sulphur imported from America, and undoubtedly the same holds good for New Zealand.

The report ipmlcd dc;,| s extensively . nitrogenous and potassie fertilisers, and with such matters as manufacturing, ITg and distribution costs, all of which are important, but which must be dealt vitli at a. later tin. to.