NITROGENOUS MANURES.

Press, Volume LXV, Issue 19670, 13 July 1929, Page 4

NITROGENOUS MANURES.

THE WORLD'S NEEDS.

SUGGESTED N.Z. SCHEME. frsou. ova o-rtt cas*Bs?ojrsj6ST.) LONDON, May 8L A certain scheme that has been suggested for obtaining synthetic nitrogenous manures in New Zealand has been the subject of conversation on more than one occasion in London recently. One can visualise a time when all the British countries will act together as one great economic unit, when every part of the Empire will have in mind the whole Empire when arranging its affairs. That time is not yet. To an ordinary business man a scheme for the fixation of nitrogen from the air in the wilds of New Zealand with an initial outlay of many millions of pounds is a matter of money and markets. Th 9 power is there in the cold lakes if they were tapped by means of a tunnel from the Sounds.

The harbour accommodation is there, and synthetic nitrogenous manures could doubtless be made in large quantities and at economic rates. There is the question of markets, however. Could New Zealand itself purchase enough of the produce to pay the interest on the capital needed for the plant? Australia would probably raisti high tariffs against the produce. America can and does produce its own manures. As for any other countries, there are freight and tariffs to consider. The subject of synthetic nitrogenous manures is one, however, which is of world-wide interest at the present time, and some of the facts may well be reviewed. Acidity of Sett. For some years the demand for Chile nitrates has been going down. Nevertheless, those interested in this industry have recently taken heart, because they say the synthetic manures have been found to sour the soil, and farmers are turning again to the Chile nitrates. This report I placed before Sir John Eussell, director of the Rothamsted Experimental Station, Harpenden. He has replied as follows:

'' We, in common with many other research stations all over the world, have conducted experiments on synthetic nitrogenous manures and on nitrate of soda. It is certainly true that with abnormally heavy and continued doses of sulphate of ammonia, for example, one can turn a soil acid, as was the case with the Woburn experiments done on light sandy soil. It is equally true that with heavy doses of sodium nitrate the soil can be turned into an alkaline condition, and its tilth seriously damaged. In actual farming practice, however, with the amounts of fertiliser used, there is no risk. The more common trouble in this country is acidity due to the economic impossibility of applying the heavy doses of chalk or of lime that were customary about one hundred years ago, but there are many experiments showing that in such cases the slight tendency of ammonium salts to increase soil acidity can be held in check by small dressings of lime. On the whole there is probably a tendency to employ ammonium salts rather than nitrate of soda in those cases where there is a likelihood of heavy rainfall occurring shortly after the application. The nitrate of soda may then be washed down below the range of plant roots, whereas the ammonium salt, which has to be changed to nitrate by biological action before it is available for plant food, is not washed ont to the same - extent.''

The World's Output. Three countries are now in cooperation and control of the atmospheric nitrogen industry—Germany (with two important plants), England (Synthetic Ammonia and Nitrates, Limited, a branch of Imperial Chemical Industries), and the United States (with several large factories). The world's demand for inorganic nitrogen is increasing at the rate of about 100,000 tons per year, and according to reports of several individuals thoroughly conversant with the situation, there is no expectation of any lower rate of increase in sight. The following table shows the world's output for the years ending June 30th, 1925, 1926, and 1927: Tons of Nitrate for Year ending Chile 1925 1926 1927 nitrate 421,000 855,000 298,000 By product ammonia 302,000 330,000 841,000 Fixed atmospheric nitrogen 459,000 641,000 807,000 Total 1,218,000 1,326,000 1,446,000 From these figures it can be seen that fixed atmospheric nitrogen not only supplied the increased demand of 100,000 tons of nitrate per year, but it also made up the difference due to the falling off of Chile nitrates. This decrease in Chile nitrate amounted to over 50,000 tons per year for the years under review, so that the increase in fixed atmospheric nitrogen has been approximately 15,000 tons per year. Even with this large yearly conexpansion it is believed that the saturation point in consumption of nitrogen is not yet in sight, and that there is room for all producers now engaged in the industry. I am indebted for the figures above quoted and for other information contained in this article to a volume by Mr Frank A. Ernst —"Fixation of Atmospheric Nitrogen"—published by Messrs Chapman and Hall as one of their Industrial Chemical Mongraphs; and to articles appearing in "Nature." It is considered that the field for the consumption of nitrogenous fertilisers is capable of almost unlimited extension. Russia, Argentina, Canada, Australia, South Africa, are practically virgin fields for the use of manufactured fertilisers, whilst of all the countries that already use them, only Germany, the United States, France, Great Britain, Holland, and Italy are the important consumers. The Three Processes. Chile supplies 20 per cent, of the world's inorganic nitrogen consumption, the by-product coke ovens supplies, 24 per cent., while atmospheric nitrogen fixation processes supply 56 per cent. Of the 807,000 tons of nitrogen represented by the 56 per cent, from the atmosphere, only 39,000 tons or less than 5 per cent, was fixed by the are process, 175,000 tons or less than 22 per cent, was fixed according to the cyanamide process, whilst 593,000 or over 73 per cent, was fixed according to the direet synthetic ammonia process. All statistics (says the author above mentioned) point clearly to the fact that the important source of fixed atmospheric nitrogen of the future, as it is at the present, will be the direet synthetic ammonia process. The maximum annual capacity of all the plants now operating is 720.000 tons of nitroi, ge n per year, whilst there is under actual construction additional capacity of 225,343 tons of nitrogen or nearly 1000,000 tons capacity operating and under construction. Germany, of all the countries of the world, » b ? f ** s**■ 68 * producer,

and during the year j.926-27 her production exceeded consumption of Chile nitrate even for 1917, the year of greatest consumption. Of 593,000 tons of nitrogen fixed in the world for the year 1927, the plants of Germany fixed 440,000 tons divided into 125,000 tone fixed by the Oppau plant, and 315,000 tons at the Leuna-Werke at Merseburg. The closest competitor is the Synthetie-Ammonia and Nitrates, Limited (Imperial Chemicals Industries), now operating a direct synthetic ammonia plant at a capacity of 22,000 tons of nitrogen per year for fertiliser materials, actually erecting an additional plant for 53,000 tons per year, and planning further increased capacity of 75,000 tons, bringing the total capacity of the plant to 150,000 tons of nitrogen per year. In the United States the combined capacity of the seven direct synthetic ammonia plants is 28,000 tons of nitrogen per year.

Among the more promising new outlets for nitrogenous fertilisers is their application to meadow and pasture land. Up to a year or two ago only arable land had been fertilised in this manner, but German manufacturers initiated a series of large-scale tests on the use of nitrogen, with or without phosphates, for grass land, arid the results have shown that the treatment is economically profitable, provided that due regard is had to the nature of the soil and the vegetation, although the increased returns are lower than in the case of arable land.