BASIC SLAG.

Kaipara and Waitemata Echo, 28 February 1912, Page 4

BASIC SLAG.

The Kuakura Farm of Instruction ha» conveyed many important lessons in the past as to vaJue of ba?ic slag as a manure for the soils of the Waikato especially in the top-dressing cf pastures, and this season agaiD further demonstrations of its value are being furnished. A striking example of the application of slag in the manuring of mangela is provided. Two lows in the mangel crop were left unmanured, while the rows on either side were treatbd Nat the rate of 5 cwt, of slag and 80 lb of potash per acre. The effect is outstanding. In the unmanured rows few plants germinated, and these are of a stunted character. On the basic slag lows the roots germinated well and show splendid development. While'the slag has made this fine showing it is only fair to say that basic superphosphate promises to give the best result. This experience is a repetition of that at the Mouma~ haki Experimental Farm last season. It is a common misconception that basic slag is alow in action. Tho ex~ perience at Kuakura and other farms of the Department emphasizes the incorrectness of this view. As a matter of fact, basic slag is generally just as quick in action as superphosphate. It i» practically instantaneous in its action either on pasture or root crop, but whether this effect is mechanical or chemical is not known. The use of superphosphate will give a larger bulk of crop ana a heavier tonnage of roots, but the feeding value will not be oO high as where basic slag has been the stimulating agent. It has been proved that the greater acidity of superphosphate encourages club-root disease, ■while basic slag kas the opposite ef^ feet.