PHOSPHATIC MANURES

Dominion, Volume 10, Issue 3192, 17 September 1917, Page 8

PHOSPHATIC MANURES

SOURCES OF SUPPLY IN NEW ZEALAND. y

!.' ""Tho decrease in the net amount of ' phosphatic fertilisers imported during !- ttio year by about 38,000 tons is a warn. i ' ing that should not bo neglected, in view S of tho possibility of a much greater > 6hortage in the coming season,'* says I Jlr.vß. C. Asian, head of the chemistry. > section oi the Agricultural Department. ";■ "The Egyptian deposits, the.value of : -which, to New Zealand' was pointed out ' Joy the writer some years ago, have furi Dished quite a substantial proportion I. (8000 tons) of the, total imported phos>Y'phates, and are capable of much. larger \- development. Mixed with superphos. \ phate this Egyptian phosphate makes a ;. more useful compound on some soils in : the same way that basic slag may be I improved by mixing with superphos- ■ . pb'ato.' . i' '"Attention should bo called to ' the r .waste of phosphates in Now Zealand. ' Modern sewage disposal is responsible '■' for'..-a-: great waste of phosphate, but a I .waste seemingly inseparable from out [western ideas of civilisation. A waste i which might well.be stopped at.onco js. > that attendant on the disposal of hsh i refuse. This is a valuable artificial f eri tilisor.. After tho 23 per cent, of oil i lias been expressed, a sample contained ; ; 18 per cent, phosphoric anhydride and ' ' 3.8 per cent, nitrogen, worth, according ; to present prices, about £B''los. per ton. f Tho bones which accumulate round ; every farm and station house aro a valui able manure when broken up. This is ■ somewhat, difficult if no bone-reducing i machinery be available, .but they may be i "reduced to a-fine state cither by fe'ri'■/. mentirig in a compost heap or by buru- ; ing, when they may be easily reduced to i a powder. '~.',, "Two explorers subsidised by a Liovern- '; ment research grant, are busy in' CanV torbury endeavouring to find a phosi phatic limestone. A sample received i from Hawke's Bar contained 73 per cent. i carbonate and 0.65 per cent, phosphate 'i■■■ of. calcium. Tho process' of making ' Jalmaer phosphate is suitable for troati; - ing low-grade siliceous phosphates vn- : contaminated with carbonates, : and is J" suitable for some New"Zealand P»os- • pbates, especially when cheap hydroi chloric acid could be made- by elcctroly- ; tic processes. Much discussion has arisen '- concerning tho merits of tho various j methods of conducting the citno acid S test for available phosphate in basic fer- , tilisers' but a recent research in Britain ': tends to'throw discredit on tho citric I method altogether. Specimens of phos- ': -nhato rock as examples of what to look \ \ for have-been supplied to the public as : before."-