CLASSICAL HELDS.

Otago Daily Times, Issue 19046, 17 December 1923, Page 8

CLASSICAL HELDS.

EOTHAMSTED EXPERIMENTAL STATION. SEVENTY YEARS OF RESEARCH. NAURU ISLAND PHOSPHATES. By 1. J. Pemberton. • 1. LONDON, November 1. Possibly if one were a farmer in England one would know a good deal about the Rothamsted Experimental Station at Harpenden—juat. as much, indeed, as the agricultuiyst in New Zealand knows about the Government establishments at Ruakura, Weraroa., or Ashburton. But those who are not specialists might go on indefinitely without knowing anything about this remarkable station for agricultural research, unless it wore brought to their notice. Eothamsted, amongst its multifarious investigations, is carrying on experiments with Nauru Island phosphate, and the pursuit of any useful information on this subject brought me into personal contact with the wellknown scientist, Sir E. John Russell, who is the director, and the SO or 60 scientists connected with the institution. A mere recapitulation of the work done, as seen in annual reports, fails to claim the attention of the uninitiated. A visit to the laboratories and the experimental plots is quite a different matter. The science of plant growth becomes something very real. One begins to realise what a tremendous field of study is open to the primary producer. One gains a new respect for all whose lot it is to rear the succulent mangold or the humble potato. Here are men and women, representing the best scientific brains of the country, inspired with the enthusiasm of the explorer, devoting the years of their life to unravelling the mysteries of Nature underlying plant growth in all its various aspects and a hundred and one other prouiems which govern the economic production of field crops. A PUBLIC BENEFACTOR. It was as far back as 1843 that Sir J. B. Lawes realised that if exact knowledge was to be gained there was the necessity for continuity in experiment. Parts of his estate at Harpenden he therefore set apart for these continuous trials. The plots are all within sight of the old manor house still in the possession of his descendants. One field was assigned to each crop and divided into a number of plots, each receiving a different manurial treatment. Each field was drilled year after year with the same crop, and every plot received annually the same quantity of the same manures. Systematic observations have been fnade of the yields under varying conditions, and information has also been obtained as to the chemical composition of the crop. There is the Broadbalk field of 11 acres which has been continuously under wheat since 1843; the Hoos Field of five and a-half teres, which has grown barley continuously since 1852; the Barn Field of eight acres which has hod roots since 1843, and mangolds since 1876; the Park Grass Field of seven acres, which has grown grass for hay since 1856; and the Agdel! Field of three acres which has been subjected to the four-course rotation since 1848. For very many years the work was maintained entirely at the expense of Sir J. B. Lawes by direct payments. In 1889 he subscribed vICO,OOO to an endowment fund known as the Lawes Agricultural Trust,'the income from this invested in Consols being £2400. In 1911 the Development Commissioners madb their 1 first grant to the Station, and since then Government grants have been made annually. For the year 192223 the Ministry of Agriculture have made a grant of £22,030. Sir_ J. .B. Lawes was associated in his work with the eminent scientist. Sir J. H. Gilbert, for a period of nearly 60 years. Lawes died in 1900 and Gilbert in 1901. They were succeeded by Sir A. D. Hall from 1902 to 1912, when the present director. Dr E. J. Russell, was appointed. NAURU PHOSPHATE. , Very many thousands of farmers are conducted over- the laboratories and-plots each year, and the Whole staff have acquired the art of imparting knowledge to visitors most,courteously and .in .tablet: form,'aa it were. Sir John Russell was_ kind enough to introduce us to our day’s investigations, and, incidentally, to toll us something'about Nauru Island phosphates. It seems that Nauru phosphate was put down on several hayfiqlds in 1922, without any marked result in the .crops daring the. first season. No definite statement regarding results can be-made apparently for a year or two yet as it is a slow-acting 1 phosphate. Sir John, however, was of the opinion that Nauru phosphate would do better if in the crushing it /were subjected to the 120 linear inch instead of 100 (i.e., 120 apertures to the linear inch instead of 100). Investigations ore at present proceeding with reference to other slags with the idea of passing them through a finer mesh, and manufacturers do not anticipate very gj-eat trouble in adjusting their existing machiThe firm in England which has practically a monopoly of the Nauru Island substance is using it largely for the manufacture of superphosphates. ■ THE ROMANCE OF 7 MANGOLDS. The fust classical area examined under the guidance of an expert was the Earn Field with its crops of mangold. Here there are plots of roots growing with every variety of stimulant, and with none. There is a plot which has been left without any form of manure since 1856. The result as compared with others well nursed is veryobvious. Last year it produced 1.72 tons of root and 0.69 tons of leaves to the acre. Its most successful competitor was that plot which had been • treated with ' farmyard manure, superphosphate, potash, ammonia salts, and rapecake. The resultant l yield last year was ; 31.55 tons of roots and 6.34 tons of leaves per acre. The whole field is divided into 35 plots. Down one of the strips (which embraces five plots) the soil is treated yearly with farmyard manure. Another whole strip is treated with farmyard manure, superphosphate, and potash; another strip with complete minerals, and so on. Taking the plots in the cross direction,. we have a strip of seven plots treated . with rapecake; another strip of five plots with ammonium salts and rapecake. The results of all these treatments, taking the average for a series of years, cannot fail to be interesting to farmers in New Zealand. The land, of course, is not of the best but the comparative results are easily apparent from the following table:

§ §1 £ |o a l» *s~ <cs 5 .go gs gS. 3 |“- - 2 Is' |U iS j?, E «3 Ka Tons Tons Tons Tons Tons per per per per per sicre. ucre. acre. uore. acre. 1. Farmyard manure only ... 17.8 26.4 22.0 23.8 23.8 2. Farmyard mannro, super potash 10.2 27.0 24.8 27.3 26.2 3. Complete minerals'- ... 4.8 17.8 14.8 26.0 21.1 4. SuForpbosph o * lo only 4.6 14.9 6.7 9.1 10.1 5. Super and potash 4.1 15.5 _ 14.0 22. C 13.2 6. Super sulphate of mag. and sodium chloride 9.9 17.4 15.5 23.0 ]9.6 7. None 3,5 9.9 5.4 B.G 9.0

It is interesting to note that these important results will bo graphically illustrated in the British Empire Exhibition next year. In this connection Miss W. L. Boys-Smith (formerly of Otago University) has given her services to reproduce in water colours an example of the root crops grown under all these varying conditions. NATURAL LOSS OF NITROGEN. Before leaving the vicinity of the mangold plots wo inspected the Apparatus for recording the meteorological conditions under which the crops are grown throughout the changing years. There are the usual rain gauges and thermometers, but beside these there is a complete section of the soil enclosed in concrete and undermined. The width of this earth section is about 12 feet, and the depth some 14 feet. The object is to catch the drainings from the section for analytical purposes. It in found in this way, for instance, that filb of nitrogen per acre are lost from the fallow soil each year. In the ordinary course of events this would penetrate down to the permanent water reserves and reappear in mineral springs. Passing on to the plots whore the fertilising value of basic sla<* is tested, one learned first of all that the up-to-date

methods of sbjel manufacture leave a slag of inferior ' grade. The percentage of phosphate has fallen considerably. In these fields the actual amount of phosphate applied is the same, so that the low-grade slag is necessarily put on in greater quantities than the high-grade. For instance, on one field 2631 b of Nauru phosphate per acre has been applied, while in another 4111 b of Nauru' low-grade slag phosphate per acre have been applied. The influence of the various slags-is seen not, directly but through the resultant fattening propensities of the crops on flocks of sheep. There is, of course, a possibility of error on account of the individual characteristics of the sheep employed, though naturally they are all of the same breed and ago. The possible errors, however; are counteracted by the continuity of the tests. HAT CROPS. Just in front of the old manor house are the park grass plots which have been under observation since 1856._ Here each plot is divided into two sections—a limed and an unlimed half. There are 23 plots, and it is possible here to refer to only a few of the results. There is the unmanured plot which last year yielded 27.9 cwt of Hay per acre for two crops on its unlimed section, and 24.10 wt of hay ner acre on its linied section There is the plot with a complete mineral manure and double dressing of ammonium salts each year, and this last year yielded in the two crops 41.4 cwt of hay on the unlimod section and 68.7 cwt of hay per acre on the limed section. A plot with complete mineral manure and treble dressing of ammonium salts and silicate of soda produced last year in the two crops 74.2 cwt on the unlimed section and £9.6cwt per acre of hay on the limed section. WORLD’S MOST BOTANISED AREA. The area, too, is a hapny hunting ground for the bota list. Probably no concentrated area in the world has been so intensively botanised. 'I ho uninitiated may see for himself the diversity of botanical composition in the various plc-ts. Where the soil has been uhmanuretj for so ’ many years there is no operation of the principle of the survival of the fittest. Innumerable varieties of plants have found a foothold and developed a modest growth. There is plenty of room for all. Where the vitalising manures have bean appliad just a few orders have held their own to the exclusion of all less vigorous growth. • , ’ Earlier in the season, no doubt, the other classical fields of barley, wheat, swedes, and clover would hove been more spectacular. At the time of mv visit the crops had been garnered in. It is enough to say that the tabulated results of crops under every condition of manorial treatment for the last 60 or 70 years are available to anyone who desires to study . them.