Fertility of the Soil

Press, Volume LXXIII, Issue 22249, 13 November 1937, Page 14

Fertility of the Soil

An Interesting passage in the annual report of the Director* General of Agriculture refers in general terms to the problem of maintaining and increasing the fertility of New Zealand's farm lands and enumerates appropriate measures, of which top-dressing with artificial fertilisers is described as " perhaps the most import- " ant." It is certainly the one most systematically used, as well as most generally, for this reason, if no other, that it yields good results quickly; but it may be suggested that still better results would follow if other measures, such as crop rotation, balanced grazing, and so on, were more systematically applied with it. The report, however, rightly says that the topdressing with artificials is "fortunately" increasing, and points to the evident fact that where the practice has been developed "the "most striking progress" has followed, while districts where it is less favoured or impossible are " on the decline rather than the rise." A more detailed treatment of this subject would be valuable; for the report mentions only that the carrying capacity of great areas of tussocked hill country is steadily falling and that in other large areas of cleared forest country, unploughable, and with a high rainfall, " nature "rather than the farmer has control of future "development." Since the aggregate of these areas is 16,000,000 acres and slight variations in cost and price levels are enough to swing them out of profitable working, the problem they present is undoubtedly serious; and the advance of research into the technique of managing these lands is very much to be desired. But while this specialised problem .may loom largest, it is less important, in the end, than the problem of safeguarding and raising the fertility of better land. It is true that the Dominion has not made such disastrous and selfish blunders as have impoverished immense tracts of Canadian and United States farm country; but the same kinds of error are not unknown, and even where the effort to make good the soil's loss in grazing and cropping is energetic and regular, it is not by any means always fully efficient and economical. This is a point on which the Hon. W. S. Parry's recent

remarks about the value of soil tests bear directly; and the Department of Agriculture cannot too warmly encourage farmers to resort to tests as a guide to their soil management. The advantages of a constructive and protective policy in the use of farm lands are of course widely recognised as enormous; but they are probably even greater and more various than the common estimate. The farmer, naturally and properly, thinks first and last of quantitative and qualitative improvement in the produce of the land, from his own economic point of view. But the community, which benefits with him in that, may benefit in quite other ways. It was lately stated before the agricultural section of the British Association for the Advancement of Science that there is a clear connexion between the health of soils and the health of the community nourished on the products. "When this country gives more " attention to the fertility of her soils," Mr F. A. Secrett said, "her hospitals will not be so " overcrowded." The connexion is between soil deficiencies and the deficiency diseases which have in recent years been the subject of much medical research.