TOP DRESSING.

Manawatu Herald, Volume L, Issue 3945, 21 May 1929, Page 2

TOP DRESSING.

LECTURE BY MR. SCRIVENER.

Mr. F. L. C. Scrivener, Lecturer in Soil Chemistry at the Massey Agricultural College, delivered a lecture to local and district farmers on top dressing in the Town Ha'll supper-room on Saturday afternoon. Mr. J. Ross (Deputy Mayor) presided and apologised for the unavoidable absence of the Mayor (Mr. M. E. Perreau). In commencing his address Mr. Scrivener said that he looked forward to getting into personal touch with the farmers throughout the Dominion and he hoped that anything he had to say would be of help to them in the top-dressing of their lands and in the extension of their present operations in this connection. For the professors of the Massey College .to properly fulfil their positions it was absolutely necessary for them to get in touch with the farmers and to advise them in connection with their problems in order that they might be able to point examples to the students in the surrounding district and also that they themselves might become acquainted with the problems of the farmers of the district.

Top dressing, said Mr. Scrivener, was a big question and one that was occupying the minds of the majority of New Zealand farmers to-day and there was evidence of more intensive top dressing at the present than there ever had been in the .past. All over the world there was a great increase in the amount of material being added to the soil. This (material was applied for one or two very good reasons. The chief reason was perhaps to improve the physical texture of the soil or to add to it some chemical substance which the plant required and which the soil was deficient in. Another reason for top-dressing might be adherently due to the soil or the removal of some substance by the produce of the soil or the action of the rain. In any case, no matter what the reason, the deficiency could '.be put right by topdressing. His reason for placing physical improvement of the soil first was because the texture was the fundamental ground work of 'the soil and was therefore of first importance. It was no use spending money on top dressing if the land contained too much or too little water or air, as in such cases the better grasses would not grow and the expenditure of money on such work would be wasted. It was therefore necessary to look to the texture of the soil first in every case. In explaining his reference to land containing too much air or water, Mi' .Scrivener said .that sand dune country contained too much air and the allies in the soil could not fulfil their proper functions with the result that the plant roots did not develop. 'Waterlogged or swampy land on the other hand, did not have sufficient air. With regard to the local soil, Mi'. Scrivener said that it appeared to him that there was ample water at a reasonable distance below the surface but the difficulty was that the 'light soil .could, not bring the water up in the dry weather. That could be overcome by increasing the humus content of the soil. In Europe the land was improved by applying farm manure or dung, and treating the soil with gireen manure and lupin. It might be thought that the latter was possibly the best method of treating the soil of this Country, but said Mr. Scrivener, experiments already carried out had shown that this method was not as good in New Zealand .as in Europe for the reason that a take of grass could be obtained here where in could not on the Continent. (Ploughing or cultivation tended to destroy the humus. The best' thing to do in this country was to obtain a good sole of grass and keep it. The humus supplied under the grass would be sufficient to keep it. The chief problem, therefore was to get a good take of one or the better classes of grass and keep it as long as possible in order to hold the soil and then to top-dress and keep on .top-dressing. It was found that in (New Zealand grass and clover would grow without much trouble where under similar conditions in other countries it was very hard to obtain a strike. New Zealand farmers should start with top-dressing combined with judical and careful manuring of the pastures to maintain a close sward of grass, and they would find that their properties would improve and that they need not (bother about other methods of treating their land.

Having arrived at the conclusion that top-dressing was essential the next question the faa*mer was faced with was what manures to use. New Zealand had been heavily timbered in the eaiT- days and hush fires employed in clearing the country had been the means of laying down a concentrated top soil of plant food in considerable quantities. This store was now, however, rapidly becoming depleted. The store of soil material, and more particularly thto phosphates, was now 'becoming, to a great degree, deficient. This was possibly accentuated iby .the fact that tree ash contained a lower proportion »o£ phosphates than the proportion required by young growing plants. The first deficiency in the New Zealand soil was therefore phosphates and this was general throughout the country. All countries were unfortunately in the habit of regarding the soil as a store house for plant food and farmers were very much in the habit of raiding that store until it was almost depleted before thinking about putting anything hack into it. When that time eventually came a medium had to he found to convert the manures