MANURING FOR PROFIT.

Otago Witness, Issue 3881, 31 July 1928, Page 12

MANURING FOR PROFIT.

No measure perhaps in the agricultural world to-day causes more speculation than the economic manuring of grassland. The fertilisation of pastures on our run country is possibly an even more difficult matter than on ordinary farm lands, and yet a stage has been reached when the problem must be tackled, seeing that our once virgin soils cannot without fertilising be reasonably expected to deliver their maximum output of wool, meat, or dairy produce. We venture to say that no farming operation will yield better money returns than judicious manuring. Experience the world over indicates that the question of manuring warrants the careful attention of the pastoral land owner, and is of far more general importance on dairy farms than might at first be expected. In experimental work results have been obtained from the use of manures- and fertilisers by the Swedish Meadow and Pasture Association/which, though they have to do with lands in Sweden, point decidedly in certain directions, and which seem to us to be of sufficient general interest to all land holders in New’ Zealand, who, per media of their sheep, cattle, or other live stock, annually export a certain amount of produce, and in doing so deplete the soil of fertility constituents. It must be recognised that depleted soils cannot furnish the nutritious herbage of former days unless there is manurial treatment of some sort or surface cultivation and treatment on modern lines. If this is granted, we can proceed with advantage to indicate the nature of the findings of the Association in respect to those surface dressing usually adopted by graziers anxious to maintain the fertility of their grass lands. It was found that liming usually had a negligible effect on yields from pastures except on very acid soils, on which a small dressing of burned lime was proved to give as beneficial results as larger doses, while it is always more economical. Lime in quantity in some cases had a depressive effect. When, however, there was a top layer of undecomposed raw material considerable quantities of - lime were generally required to effect sufficient decomposition of the organic matter for the free establishment of the pasture plants. On the other hand, almost all soils have been found to respond quickly to the use of phosphatic fertilisers. While basic slag has been found to give excellent results on light and acid soils, it has been found in. Sweden that the necessary phosphoric acid was more easily procured and at a slightly lower price in the form of superphosphate. In general, it has been found that a basic treatment of 4001 b superphosphate per acre per annum, or the equivalent of basic slag during the first two years and a dressing of 2001 b per-acre in foliovying years, does, as a rule, increase yields from grass land by 50 to 200 per cent. Increments, it is stated, of 300 to 400 per cent.—and in certain cases even muoh more—have not infrequently been recorded. In addition to the effects on the yields, a decided improvement in the quality, palatability, and nutritive value of the herbage has in most cases been observed. On light soils a.nd loams, potash also has been found to increase yields considerably, and in such cases dressing of 751 b to 1501 b of muriate of potash per acre, when given in conjunction with phosphatic fertilisers, have given good returns. The use of nitrogenous manures in most cases has been found to increase the yield, but there have been failures. Since nitrogen, in whatever form it be given, clearly tends to increase, the proportion of grasses to legumes, its use on pastures has often been found to be rather uneconomical, but it must not be forgotten that under the modern system of grazing too much stress cannot he attached to this finding. In Germany, where artificial nitrogenous fertilisers can at present be procured at a relatively low cost, the tendency is now towards an ever increasing use of nitrogen on the'grass lands. It is claimed that vegetable protein can be procured more cheaply and with greater certainty in thia way than solely through the encouragement of the legume flora. Similar results have also recently been obtained in Great Britain. In farmyard manure we have a recognised good all-round manure. It is a pity there is not enough of it to make it worth while considering seriously. Suffice it to say, that the evidence at hand points to summer as the best time-for spreading thia manure,

it dues not then seem to impair the palatability of the pasture grass, as appears. to be the case when spread in the spring just before the vegetation has started.

Although there is ample evidence to show that the application of suitable fertilisers increases the bulk of herbage, it is more difficult to determine the quality and palatability of the grass. This is a matter of immense importance, as it would be little or of no use increasing the amount of the herbage if it was distasteful to stock. This trouble, however, is not insuperable, and instead of dairymen having to feed their cows additional foodstuffs in order to maintain the milk flow during the grazing season, they found that even their higln est-yielding cows maintained their milk llow without any addition of concentrates, while manuring on right lines also tends to prolong the grazing season