Serpentine Super

Dominion, Volume 36, Issue 16, 14 October 1942, Page 6

Serpentine Super

Sir, —Your leading article this morning, “The Key to Production,” gives, further evidence of your interest iu the important question of compulsory reversion of superphosphate with serpentine. This is most encouraging to those of us who are interested in the special problems of maximum production in wartime. Your lucid statements bring home my apparent failure to make myself clear to you. Aly whole argument was intended to show that the shortage is one of phosphate, which is the important part of super-lime mixtures; aud that the shortage of phosphate, which in fact is rationed, calls for the same strict or even stricter supervision in use as does the shortage of petrol; for neither phosphate nor petrol, as you so cogently remark, is produced in this country. Now you have assumed, presumably inadvertently, that I was arguing a shortage of lime and that farmers should not be permitted to use it. Nothing was further from my mind. I endorse the report of the Agricultural Lime Investigational Committee and all you say about it; and when you write “Many farmers wish to continue using lime,” I, say, “Let them use it by all means, and as much as they ean get”—with this simple reservation, that war conditions, including the petrol shortage,- will inevitably tend to curtail supplies of that naturally abundant material. I can even offer you references as to the many advantages of liming in a current textbook on “Soils and Manures in New Zealand.” by one L. J. AVild, M.A., B.Sc., who, if memory serves me, was formerly lecturer in soil chemistry in Canterbury Agricultural College. But the whole purpose of my previous letter was to concentrate attention on the shortage of phosphate. Of this we have no developed supplies in New Zealand, though recent investigations indicate great prospects at Clarendon, in Otago; and, if I may digress for a moment, I would say it will be no fault of the Primary Production Council if the Government itself, with or without the help of the British Phosphate Commission, does not go ahead energetically at Clarendon with prospecting, quarrying, crushing, separation, treatment, laboratory tests, manufacturing tests, field trials, and possibly even some “doubtful experimentations.”

In the meantime it is phosphate—imported phosphate—that is in desperately short supply, and to make the supply go as far as possible, and do as much productive work as possible, the Government, on the recommendation of the Primary Production Council, and for reasons which I have already set forth fairly fully, has decided that in the North Island all superphosphate is to be revei’ted with serpentine and not with lime. —I am, etc., L. J. WILD, Member of National Council of Primary Production. Feilding, October 8.

Sir, —Referring to the further letter on the question of serpentine-super over tlie signature of Mr. L. J. Wild in your Saturday’s issue. My statement was prepared in as much as I preferred to have my comments in my own words rather than your representative interpreting them for me. I do not think Mr. Wild has anything to complain at in this. Tbe official published records do not provide adequate evidence that serpentine-super is superior to lime-basie super. I therefore consider that the turning of all super into serpentine-super as doubtful experimentation. As pointed out to your representative on a previous occasion, no one type of fertilizer will give the best results on all soils and for all crops. Cases will undoubtedly be found where serpentinesuper will "give results superior to other types of fertilizers, but when it comes to a state of emergency where it is desirable to fix on one type, of fertilizer it is logical to select the one that has given proof of its general efficiency over tlie years instead of selecting a mixture which lias been on trial over so short a period. 1 would further reiterate the importance of the economic aspect. Suitable serpentine deposits are few and tar between and entail installation of special plant for crushing. liamlling and distribution and the distance of railage tnust in some instances bo great compared with the ready availability of lime deposits of which are being worked in many parts of tlie country nt places more adjacent ’to phosphate works. The arguments against the serpentine are so obvious ‘to anyone willing to understand that it is unnecessary to elaborate further. In conclusion, I venture to predict that the use of serpentine as an ingredient of fertilizers will within a short time pass to the oblivion it deserves. —I am, etc., G. A. LAM RENCE. Johnsonville, October 10.