THE RURAL WORLD

Otago Daily Times, Issue 23595, 3 September 1938, Page 3

THE RURAL WORLD

FARM AND STATION NEWS

By RUSTICUS.

h«m* of intoroit to thoaa engaged in agricultural and pastoral punufta* with a view to their publication in theao column*, will be welcomed. They should be addressed to Ruaticus, Otago Daily Timet, DunecU*.

mB-3e WOOL SEASON ROSTER OF SALE DATES Tb« following roster of sale dates for the 1938-39 season has been drawn up by the New Zealand Wool Commit' teesNovember 26 (B a.m.).--Auckland. December 2 (9 a.m.).—Napier. December 7 (9 a.m.).—Wellington. December 12 (9 a.m.).—Christchurch December 16 (8 a.m.).— Timaru. December 20 (9 a.m.).—Dunedjn January 9 (9 a.m.).—Wellington. January 14 (9 a.m.).~Napier, January 19 (9 a.m.).—Wanganui January 24 (9 a.m.).—Auckland. January 30 (9 a.m.).—Christchurch. February 3 (2 p.m.).—lnvercargill February 8 (9 a.m.).—Dunedin. February 15 (9 a.m.).—Wellington. February 20 (9 a.m.).—Napier. February 24 (2.30 p.m.).-Wanganui. March 3 (9 a.m.).—Christchurch March 7 (8 a.m.) .—Timaru. March 11 (2 p.m.).—lnvercargilL March 16 (9 a.m.).—Dunedin. March 23 (9 a.m.).-Wellington. March 27 (9 a.m.).—Auckland. March 30 (2.30 p.m.).-Wanganui April 3 (9 a.m.).—Napier. April 14 (9 a.m.).—Christchurch. April 19 (9 a.m.).—Dunedin. April 24 (9 a.m.) .-Wellington. 1938-39 SHOW SEASON ROSTER OF DATES Summer been arranged for the 1938-39 season es follows. (The list is still incomplete, and secretaries of show societies are invited to for* ward particulars of their dates as soon as they are fixed):— September 22.—Otago A. and P. Society's Clydesdale Stallion Parade, Tahuna Park. November 10 and 11.—Canterbury Metropolitan, at Acldington. November 16.—Wairhate. November 16.—Kelso. November 18 and 19.—North Otago. at Oamaru. November 19.—Taieri'. November 22 and 23.—Otago Metropolitan, at Tahuna Park. November 25.—Clutha and Matau, at

Balclutha. November 26.—Winton. December 6 and 7.—Gore. December 10.—Wyndhaim. December 13 and 14.—Southland, at Invercargill December 16.—Maniototo, at Ranfurly.

1939 January 14.—Waitati. January 21.—Waikoualtl. January 27.—Palmerston-Waihefho, at Palmerston. April 10.—Strath-Taierl. at Middlemarch. April 10.—Mackenzie Highland, at Pairlie.

ARTIFICIAL FERTILISERS THEIR IMPROVEMENT AND DEVaOPMENT MANUFACTURE AND DISTRIBUTION ADDRESS BY MR J. A. BRUCE An interesting and instructive address on fertilisers, their application, manufacture and distribution, was delivered to the monthly meeting of the agricultural section of. the Royal Society of New Zealand (Otago branch) by Mr J. A. Bruce, of the Dominion Fertiliser Company. Mr Bruce covered a wide field and embraced the whole use and value of artificial fertilisers on the farm. Very much more was known about soils and fertilisers to-day, said Mr Bruce, than was the case at the beginning of the present century. Particularly in the last 25 years, as an American professor recently pointed out, many notable advances had been made relative to soil morphology, soil composition, soil colloids, interaction of soil minerals with fertiliser constituents, methods of fertiliser application the r6le of the trace element in plant nutrition, soil testing, plant symptoms of nutrient deficiencies, mechanical condition of fertilisers, acidity and basicity values of fertiliser materials, raising the grade and concentration of fertilisers, the effect of soil temperatures on fertiliser utilisation by plants, and the actual warming of the soii in open beds for certain early crops receiving fertiliser. There was also the relatively new branch of soilless agriculture, which grew plants in sand or water through the addition of fertiliser solutions supplemented by plant hormones and other special chemicals. PROGRESS OF THE INDUSTRY Before going on to discuss the physical properties of such fertilisers as superphosphate, Mr Bruce referred to other aspects of progress in the modern fertiliser industry, and the need for constant study and research, particularly in the preparation and distribution of fertiliser, seeing that it is a national commodity of front-rank importance. Phosphorus, the most important plant food element of agriculture, was discovered, isolated and named by Brand, a Hamburg merchant and alchemist, while searching for the philosopher's stone in human urine. He made up the name from two Greek words, "light bearing." This important discovery was, however, not the real commencement of the fertiliser industry which was to come later. It was a modern enterprise, scarcely a century old. dating back to the year 1843, when John B'ennet Lawes, of D'eptford, England, put into operation his superphosphate plant, and commenced to manufacture the material on a commercial scale. The history of the fertiliser industry was not devoid of romance and was associated with the names of many great men such as Sir John Lawes. whose lives were devoted to its improvement for the welfare of their generation and posterity. The manufacture and distribution of fertilisers had had many ups and downs, and was still passing through gradual stages of adjustment and evolution all over the globe. He would particularly emphasise the word distribution because a great deal of attention could be devoted to this aspect in this country where inland transport facilities were not of the best, and where packhorses were sometimes employed and contract top-dress-ing undertaken by gangs of men in the back country. "In the case of fertilisers, the distribution is still done with the bag as the main form of container. There is not much of the material sold in the unbagged state these days. One question we might well ask is there not some better means of distribution than by means of the fertiliser bag In the case of transport of fertilisers, the railway, the steamer and lorry still carrv the bulk of material from works to farmers. However, we cannot shut our eyes to the progress being made* in transport and distribution by aeroplanes and autogyros in certain overseas countries, and it looks as though '.n years to come fertiliser works will require landing fields and the farmer will very likely follow the fertiliser treatment of his paddocks from the air r t > han use a ha "d or horse-drawn distributor. Possibly the fertiliser manufacturer will carry out the programme of distributing fertiliser by air in addition to manufacture. Mr Bruce said that he was merely drawing attention to this newer aspect of distribution of fertilisers which is showing some signs of gradually developing in some air-minded countries, such as Canada, and may' bring far-reaching changes in its wake in the future, possibly eliminating the fertiliser bag, drill, lorry, etc. Apart from these possible avenues of future progress there is the immediate and far-reaching question of the mechanical condition of our so-called straight fertilisers and mixtures and their relation to efficiency and costs. Although the standards of chemical content of fertilisers are fixed and controlled by Statute there are no regulations expressly governing the physical condition of fertilisers, with the exception of basic sla? « and ground phosphate rock, in this country. These two insoluble fertilisers are rightly required to be ground to a minimum fineness of 80 per cent, of the material passing through a sieve containing 100 meshes to the linear inch. EFFICIENCY OF PHOSPHATIC FERTILISERS There were, of course, several main factors, said Mr Bruce, which affected the mechanical application of fertilisers to the soil and influence their efficiency and cost to the consumer either during or after distribution by hand or by machinery. For instance, there was the problem of what size and grading of particles in a fertiliser was desirable to secure the most economic results-for the many different types of crops. The subject was a particularly

wide and complicated one, and it was proposed to deal as previously pointed out with only a few of the main aspects. Fortunately there was now an increasing realisation that soil reaction had an important bearing on the efficiency of purchased fertilisers, and that proper soil reaction without plant food was conducive to soil depletion. In other words, they can hold plant food in soils largely by keeping them acid, but plant food in the soii was useless unless properly utilised by plants. Only that which was taken up by the plant had a sales value. Sir John Russell, director of Rothamsted Experimental Station, England, had affirmed that only about 20 per cent, of applied phosphates were utilisable by plant life, and other authorities were of the opinion that the utilisation of phosphates was an exceedingly variable factor depending on the soil and climatic conditions under which the crop was grown and the rate of fertiliser application and so forth. It would also be observed that slowlyacting feeding materials, for example, could seldom be applied profitably to quickly-growing crops. Likewise, expensive materials cannot always be applied profitably to crops of relatively low market value. As weather conditions were constantly changing, the agricultural value of a fertiliser must necessarily vary somewhat from year to year, even when the same variety of crop was grown on the same field, and the same rate of application was used.

"When phosphates are added to soils," he said, "chemical reactions, some of which are of a complex character, take place. If the phosphate is a water-soluble one, the principal reaction is that of fixation, in which case some fixation compounds of the soil combine with the soluble phosphate applied to form more or less insoluble phosphates. Common fixing elements in the soil are magnesium, calcium, aluminium, iron, and titanium. Iron compounds usually fix phosphates the tightest, while magnesium and calcium and aluminium phosphates are not so tightly fixed. Soils vary in their content of active fixation compounds and as a consequence they vary in th; tightness with which they fix phosphates. Professor Truog, of the University of Wis-

consin, U.S.A. (1932), has concluded from researches dealing with Wisconsin soils that superphosphates are reverted into the not readily available basic iron phosphate, for instance, when applied to soils that are more than very slightly acid (p. H of 6.2). When water-insoluble phosphates such as bonedust and finely-ground raw rock phosphate come in contact with the soil, they may be made either more soluble or in some cases they may be made less soluble. In some acid soils the increasing of the insolubility is very important. It may thus be seen that there are two oppositely acting groups of forces at work in the soil—one making the phosphates more soluble and the other less soluble. Degree of acidity of the soil measured in terms of p H, amounts of basic elements, organic matter, sand, silt, and clay are some of the soil factors influencing availability of insoluble phosphates. Soils, of course, vary a great deal in the relative proportion of these ingredients. It would appear as a matter of fact that there is a much greater chance of arriving at a solution of some of the most baffling problems of fertiliser response in many districts of this Dominion by means of intensive soil studies and systematic soil surveys conducted by trained soil chemists rather than by means of the usual observational fertiliser trials. The aluminium and iron content of many soil types in New Zealand is high, and the fixation of water soluble phosphate as found in superphosphate by compounds of these elements, presents an Important line of research to be taken up in the economics of fertiliser use." GRANULATED FERTILISERS It had already been well proved, said Mr Bruce, that limestone, rock phosphates, as well as other insoluble fertilisers and soil amendments, were much more effective in increasing crop yields if they were applied in pulverised form, consequently it seemed quite a radical departure several years ago when the more granular type of superphosphate appeared on the market as a competitor of the fine or dusty article. However, there was an important difference between ground limestone or rock phosphate and readily soluble fertilisers such as v superphosphate. The difference lay in solubility. Limestone, rock phosphate and other insoluble materials must be finely ground in order that they might become more accessible or available to plants through the solvent action of the soil solution and the plant roots. On the other hand, the nutrient compounds in chemical fertilisers such as superphosphate were already in watersoluble and readily available forms, and did not need to be finely pulverised to facilitate their availability in the soil. In fact, it was necessary in the case* of superphosphate and potash in some soils to devise means of protecting these readily available fertilisers from too rapid fixation or reversion to insoluble forms, such as iron phosphate. In many classes of soil in New Zealand it would appear that the rate of fixation or reversion of both phosphate and potash into insoluble forms was very rapid and their effectiveness as plant foods was consequently greatly reduced. VIRTUE IN THE GRANULE "Any material or mixture in the form of grains that are more or less uniformly adjusted in size and shape is said to be granulated,' 1 said Mr Bruce. " When applied, especially on acid soils, the finely divided particles containing the water-soluble phosphate of the ordinary fine, dusty superphosphate are dissolved and rapidly dispersed throughout the layer or zone in which they are deposited. The phosphate as previously pointed out tends to become combined in insoluble compounds with iron aluminium and titanium, and may thus be withheld from immediate use by the crop. Superphosphate in the well-graded form as regards right size of particles, offers less exposure to the action of the soil bases mentioned.

The granules decompose gradually, shedding coat after coat and keeping pace with the crop's draft of phosphate from the soil solution. The rapid leaching of soluble fertilisers, which is a problem closely bound up with that of fixation in some soils, is also retarded by suitable granulation. The soluble fertilisers that leach most readily from the soil undergo least fixation as a rule and vice versa. Of the compounds ordinarily used as fertilisers, nitrate of soda undergoes the least fixation in the soil and superphosphate the most." "In passing, it may be as well to mention," said Mr Bruce. " that consideration should be given to the fact that soils are dynamic and should not be thought of merely as a mass of Inert material. Physical, chemical, and biological changes are continually taking place in soils, and these changes, acting In unison with climatic forces and the plant itself, influence the efficiency of any fertiliser applications. "Soils are also greedy, and, as we have already observed, have certain strong bases —iron and aluminium compounds—which absorb and retain the soluble, monocalcic phosphate applied In the fine powdery or fluffy form of superphosphate. The major portion of the phosphate may thus be used up in satisfying the soil's greed rather than its need, and the crop gets what remains over. This amounts to feeding the soil instead of the crop. The soil, as we all know, competes with the plant for the available phosphate supplied in the form of fertiliser. Because of this fact it is often necessary to apply from five to ten times as much phosphate to the soil as will be recovered by the increased yield of the crop resulting from its use. The only effective way to overcome this difficulty lies in granulating the material or in some cases by reverting the water soluble form of phosphate into the citrate soluble form beforehand with the aid of lime. Dicalcium, or reverted phosphate, the product of the artificial reversion of the monocalcium phosphate of superphosphate by the manufacturer, is preferable to aluminium or iron phosphate, the insoluble, unavailable, uncontrolled reversion products of soil reaction. "The soil can come in contact with

only the surface of the fertiliser granules. The roots of the young plants soon surround the granules and absorb the nutritive matter as it diffuses out of them. In this way a larger percentage of the phosphate applied is available for use by the crop. "In the case of apples and other fruit trees, growers find it best to examine the feeder roots and put the heaviest amounts of fertilisers underneath the branches, where most of the feeder root system occurs. "In the feeding of all plants it is essential that their root systems be carefully studied to get the right uniform placement of fertilisers. This will be touched upon briefly further on in this paper. Under dry climatic conditions both the granulated and fluffy forms of superphosphate may not be successful in promoting the growth and improving the yield of fruit trees for the reason that the granulated material may be rather too slow in its action and the fluffy article may become locked up in insoluble compounds with iron, aluminium, etc. In studying these qualities it is desirable to compare ordinary fertiliser mixtures with mixtures of homogenous granular fertilisers having a well-adjusted proportion of particles of varying sizes. Such comparisons should be made on soils that represent a wide range both as to leaching qualities and fixation powers.

Under such conditions in the United States of America it has been found necessary to inject suitable fertiliser solutions into the soil within range of the feeder roots to enable the orchard trees to be properly fed. The Technical Committee set up in this country in the year 1931 by MiGeorge Forbes to report on fertilisers and methods of distribution referred to the fact that fertilisers in a granular condition produce less scorching than those in a very finely divided form. This, of course, particularly applies to the highly soluble materials of the nitrogenous, concentrated phosphate, and potassic group. The method of overcoming both the rapid fixation or reversion of soluble phosphate to unavailable, insoluble forms as well as the scorching of plants by soluble fertilisers is by adjusting the sizing of the fertiliser particles. In the case of plants in the row or hill, rapid fixation can also be overcome by placing the fertilisers in concentrated bands close to the plant. In both cases there is less surface exposed to fixation, and there is a greater concentration of the soluble fertiliser at the areas of contact with the soil, thus enabling ihr j fertiliser to saturate or overcome the fixation elements where the fer:il;ser is placed, and as already pointed on! it permits a lager proportion of the fertiliser to remain in a readily available form in the soil for a much longer period. SUITABLE GR/""•'-' OF PARTICLE SIZES "Since it is fluiiy i..£jorphosphate especially that is 'fixed' in an insoluble form in the soil, it is this article in particular that would be expected to show the greatest advantage from use in the right granular form in this country. However, if a mixed or socalled ' complete' fertiliser is used it would be difficult to obtain uniform distribution in the field if the phosphate was in more or less uniformly granulated form and the other ingredients in a fine or pulverised state. This is because, as the fertiliser urill moves over the ground, the jiggling and bouncing will cause the fertiliser ingredients of different particle size and specific gravity to separate into layers so that the finely ground, heavy materia] would sow first and the larger particles would rise to the top and not be sown until the drill was nearly empty. Consequently, if a mixed or complete fertiliser is used, the aim should be for the granules to be of uniformly graded or homogenous mechanical composition as possible. This will tend to prevent segregation of the different ingredients and ensure uniformity of the ratio applied under field conditions. When segregation takes place the composition of a mixture applied in certain portions of a field

may be very different from that applied in other portions. Segregation of particles also occurs to a slight extent in most commercial fertiliser mixtures during transport and handling from the time it leaves the works until it is put on to the soil. Apparent density varies with the size distribution of particles and therefore the size of the bag required to hold a given weight of substance depends upon its particle size distribution. This is a most important fact and explains the necessity of not having too large particles in the fertiliser bag. If the particles are too large the bag may be overfilled to obtain the same weight as can be obtained in a normal sized bag with small and medium sized particles. It is, of course, well known that very finely ground material is less free-flowing and more difficult to drill uniformly because it compacts more due to cohesion and friction between the particles and tends to "arch" and then suddenly crumble and surge through the drill for a short while, and then pack again. On the other hand, the rightly granulated material containing fairly uniform grades of particles, flows much more freely and drills more uniformly. It has been repeatedly shown overseas that fertilisers are at least 50 per cent, more efficient when uniformly applied, and that most implements cannot apply fine or fluffy fertilisers uniformly, but make a fairly uniform application with the right type of homogenous granular fertilisers or those which are physically well adjusted as to particle size. With the properly granulated fertilisers, drillability is imposed by greatly decreasing the cohesion and friction between particles. Handling charges are also reduced. Within recent years the trend has been towards the manufacture of a somewhat higher proportion of plant food constituents both in straight fertilisers and in mixtures. This often means that less quantities are employed. The higher the analysis or concentration of the fertiliser, the more important it is that it should permit of an even distribution. Further, in recent years with the sharp rise in wages, increase in cartage costs and scarcity of suitable labour on the farm, the practice of applying fertiliser

by machine rather than by hand is followed where practicable. Freeflowing materials are therefore essential to the farmer to-day. Fertilisers cannot be uniformly distributed in the field if they cake or become sticky; if they undergo segregation on handling or if their drillability is poor for any other reason, such as fineness. They should be free from dust, easy to handle and apply either by hand or machinery, and should have no tendency to stick to leaves of plants or to the hands of the person applying them. The granules should flow freely and not bridge over in the distributor nor should they cement together on standing; the machine should stop the flow when it is standing still. A finely divided condition not only impairs the drillability of a mixture, for instance, but it promotes caking owing to the greater surface area exposed to humid conditions of the atmosphere; to increased cohesion between particles and to the tendency of large particles to grow at the expense of smaller ones

A SPRING WHEAT SUITABILITY OF MARQUIS EARLY MATURING QUALITIES The suitability of Marquis wheat for spring sowing was strongly stressed last week by several North Canterbury farmers and millers. A farmer on clay downs in the Sefton district, Mr R. Peach, expresses the opinion that Marquis wheat should be especially suitable this season because of its earlier maturity. Last season he had had great success with Marquis. He sowed a paddock in October, the seed making a wonderful response. Mr J. Tutton, a prominent miller and farmer of the Rangiora district, expressed the opinion that farmers were making a very wise investment in sowing Marquis wheat this spring. From his own experience he had every faith in the variety and if more of it were grown in the Dominion, New Zealand would be able to produce the best bread in the world. In addition to Marquis wheat being worth 4d a bushel more than Tuscan or Cross 7 it could be relied upon to mature early. He cited an instance of where a farmer last season drilled Marquis in the second week in November and who obtained a satisfactory yield. Growers who were unable to sow crops in the early spring through the saturated condition of the ground could be confident of obtaining good results from Marquis wheat if they sowed it later. Mr Tutton added that although the advantage of cultivating Marquis wheat was sometimes questioned because of its being subject to shelling by strong winds, Marquis wheat stood winds better than Jumbuck. His area of 400 acres sown in Marquis wheat last season convinced him of its dependability. That North Canterbury land was ideally suited for the cultivation of Marquis wheat was the opinion of Mr H. Archer, another miller in the Rangiora district. He agreed with Mr Tutton that it was a good crop for late sowing, and farmers would be wise to plant Marquis in preference to Tuscan. Marquis wheat was grown extensively in Canada, and he saw no reason why it should not be grown with equal success in the Dominion.

The foregoing opinions are of direct value in view of the predominating position held by Marquis wheat in Canada, the country of its origin. Millions of acres of the North-Western provinces had been found unsuitable for growing the existing varieties on account of the short spring and summer seasons, but the evolution of the Marquis variety—" the 90-day wheat ' —brought these millions of acres into productivity. It is the advance in Canadian acreage, brought about by the Marquis variety, that has mad** Canada the"principal wheat exporting country in the world.

. Canadian experience would point to a crop, sown and come to maturity in 90 days, that could be planted in September and be ready for harvesting by the New Year. Such a restricted period in the soil, though possible in Canada, where the thaws are sudde-i and give the crop a quick start, it would be unwise to base estimates so optimistically in New Zealand. , Bu* under New Zealand conditions there is no doubt that Marquis, sown any time in September, would be ready for harvesting in an ordinary season a* soon as the ordinary varieties, sown more than a month earlier.

Tests made by the Wheat Research Institute show that wheat which can secure an unchecked growth from germination to harvesting makes the best baking flour available. The capacity of a wheat to do this is largely influenced by the climatic conditions, but the fact that Marquis is less time maturing than other varieties automatically shortens the time in which it may become subject to climatic disabilities. Its quick-growing capacity reduces the normal checks. The classification of Marquis with Pearl—4d a bushel higher than Tuscan and Cross 7 —shows that the baking quality is highly esteemed, possibly a result of its less uninterrupted growth. In a favourable spring season in the South Island Marquis has been known to yield 60 bushels an acre. It cannot be claimed from experience here, however, that it is a befter yielder than other varieties, but it stands up to the wind better than Jumbuck, and again its shorter period of growth renders it less subject to the vagaries of the weather than longer growing varieties.