TARANAKI IRONSAND

New Zealand Herald, Volume LXIX, Issue 21377, 29 December 1932, Page 11

TARANAKI IRONSAND

Sir,—According to a report from Taranaki, an attempt is to be made to utilise the deposits of ironsand which abound on the Taranaki coastline to produce fertilisers which combine the ferric salt series. It is reported that manufacturing works will be erected at New Plymouth and Hangatiki. From these locations it appears that Hangatiki lime will play a part in its manufacture. Ferric salts, plus calcium, would be useful on bush-sick areas, but very detrimental to areas whei-e fertilisers such as sulphate of ammonia, sulphate of potash and superphosphate already do all that is required. Good mixtures for bush-sick'areas are as follows: (1) Basic slag, 95 per cent; nitrate of soda, 2.5 per cent; potash salts, 2.5 per cent. (2) Basic super, 90 per cent; nitrate of soda, 3.5 par cent; potash salts, 2.5 per cent; sulphate of iron, 3 per cent; di-oxide of manganese, 1 per cent. The writer has had experience in the use of forric salts as a fertiliser and the quantity used per acre should not exceed 61b. Most farmers shy clear of a farm which has an iron pan close to the surface. Ferric phosphate is formed when phosphoric acid (a water-soluble plant food) comes into contact with iron in any form. Plants cannot assimilate ferric phosphate; thus when iron is applied to, or is contained in, the soil and superphosate is used as topdressing, the water-soluble phosphoric acid combines with the iron readily and is a dead loss to the farmer. Titanium.