Basic Slag.

Northern Advocate, 14 February 1912, Page 2

Basic Slag.

- The Ruakura Farm has conveyed a number of important lessons in the past as to the value of basic slag as a manure for the soils of the Wai' kato, especially in the top dressing of pastures, and this season again further demonstrations of its value are being furnished. A striking example of the application of slag in the manuring of mangolds is provided, says theDeparment of Agriculture's Journal. Two rows in the mangold crop were left unmanured while the rows on either side were treated at the rate of scwt. of slag and Bolb. of potash per acre. The effect is outstanding. Jn the un manured rows few plants germinated, and these are of a stunted character. On the basic slag rows the roots germinated well, and show splendid development. While the slag has made this fine showirfg it is only fair to say that basic superphosphate promises to give the best result. This experience is a repetition of that at the Moumahaki Experiment Farm last season. It is a common misconception that basic slag is slow in action. The experience at Ruakura and other farms of the Department emphasises the incorrectness of this view. Asa matter ofiact, basic slag is geoerally 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 disease, while basic slag has the opposite effect.