THE VALUE OF BASIC SLAG.

King Country Chronicle, Volume VII, Issue 548, 8 March 1913, Page 2

THE VALUE OF BASIC SLAG.

Discussing basic slag in a recent lecture in the Midlands, Mr W. A. Cox, of London, after speaking of ita price and judged by its unit value and its analysis, said: — "It is not too much to say that the present condition of millions of acres of grass land in the country was a reproach to owner and occupier. The question, indeed, assumed something of the nature of a national concern. Fortunately, the number of those experimenting was increasing yearly, but all too slowly, and he could stftje from personal knowledge that farmers occupying chalky and other light land and light hilly land were beginning to realise what a simple and inexpensive aid they had in slag in converting into valuable grazing much of what was formerly little better than valueless, in some cases at best serving only as a sheep run a few weeks in a year. In many instances slag alone was proving remarkably effective in improving the herbage on light soils of all descriptions and at various altitudes; but the probability was that in the great majority of cases the customary dressing of five to eight cwt., of slag per acre would need, in order to show its full effect, to be supplemented with a moderate quantity of potash (3cwt. kainit or up to lcwt. muriate or sulphate of potash per acre), on these light soils. This, however, was less necessary on light grazing land than on light hay land. Nor were the beneficial effects of basic slag restricted to grass land. Those who had most closely studied the subject recognised that the great bulk of their arable soils were as deficient in Dhosphates as was the grass land, and "responded as gratefully to proper supplies given in suitable form. Undoubtedly, an adequate furnishing of the soil with cheap, readily available and durable phosphates, especially when alkaline in character, would be assigned the place of first importance in the whole of the manurial practices of the future. There was, too, an important secondary advantage in choosing basic slag as the chief means of enriching the soil in the much-needed phosphates, viz., that, in doing so, quantities of useful lime were supplipd simultaneously and free of cost. It was becoming better understood from manurial trials, that many soils were fortified by nature with more or less liberal supplies of potash, and though much of this was not of itself in a condition that made it readily available by plants, a portion of it was soon rendered so by the lime present in slag, more so than by any other "simple" phosphatic manuring. Then, further, in relation to nitrogen, it was open to the farmer to effect a considerable saving in his outlays on nitrogenous manuring by grwoing, with the aid of slag, abundant leguminous crops, whose faculty for appropriating nitrogen from the atmosphre, and "fixing" it in the ground for the use of subsequent crops, Was immensely quickened and strengthened by the dual supply of alkaline phosphates and lime thus given. And with regard to its striking eeffcts on grass land, while its chief value was in the citric soluble phosphate it applied, the slag lime acted upon the humus so largely present in old grass land, thereby break' ing it up and "rendering nitrogen available, the grasses much benefitting therefrom.