BASIC SLAG.

Dominion, Volume 5, Issue 1355, 5 February 1912, Page 8

BASIC SLAG.

DEMONSTRATION Of ITS VAT.UE. Th© Ruakura Farm bn.s convoyed a number of important lessons iu tlic past as to the value of ,basio slag as a manure for tho soils of tho Waikato, especially in tho top-dressng of pastures, and this season again further demonstrations of its value aro being furnished. A striking example of the application of slag in Hie manuring of mangolds is provided, says tho Department of Agriculture's Journal. Two rows in the mangold crop were left unmanured, while the rows on either sido were treated at tho rate of scwt. of slag and SOlb. of potash per acre. The effect is outstanding. In the unmanured rows few plants germinated, v and these are of a stunted diameter. On the basic slag rows 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 givo the best result. This experience is a repetition of that at the Jloumahaki Experiment Farm last season. It is a common misconception that basic slag is slow in action. The experience at liuaknrn and other farms of the Department emphasises the incorrectness of this view. As a matter of fact, basic slag is generally just as quick in action as superphosphate. It is 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 and a heavier tonnage of roots, but the feeding value will not be so high as where basic slag has been the stimulating agent. It has been proved that the greater acidity of superphosphate encourages club-root'dis-ease, while basic slag has the opposite effect.