REVERTING SUPER

Auckland Star, Volume LXXIII, Issue 239, 9 October 1942, Page 4

REVERTING SUPER

LIME ADVOCATED

There would be a considerable saving to the country if limestone instead of serpentine were used to revert superphosphate, said Mr. G. A. Lawrence, an agricultural chemist, of Wellington, in contesting claims recently made by the DirectorGeneral of Agriculture, Mr. A. H. Cockayne, for the serpentine-super mixture.

Mr. Lawrence said that Mr. Cockayne's claim that three years' trials had proved that 1001b of serpentinesuper would do the work of 1001b of straight super was an important admission, when it was remembered that for many years the Department of Agriculture had advocated the use of straight super. Also added to this was the fact that serpentine-super was after all, only a form of basic super. Mr. Lawrence said that it appeared that lime was better than serpentine for rendering super - phosphate basic, since serpentine deposits were few and not always in suitable locations, while lime deposits were being worked in numerous parts of the countrv.

He suggested that if farmers were allowed to mix super and agricultural lime in the same proportions as serpentine and super were mixed, the saving to the farmer would be about £1 a ton.