OTAGO INSTITUTE

Otago Witness, Issue 3250, 28 June 1916, Page 65

OTAGO INSTITUTE

" CROMWELL DEVELOPMENT SCHEME."

Mr F. J. Williams road a paper before, members of the Technological branch of the Otago Institute on the 20th inst. on the " Cromwell Development Soheme," and at its conclusion showed a large number of designs illustrative of the work on the screen.

Mr Williams's paper commenced with some general remarks on irrigation, which was described as probably the oldest science of which we had any record. Reference was made to irrigation in the very earliest form; the Scriptures being quoted in support of its ancient origin. It was imagined that the art of applying water to cultivate land was a complicated and wonderfully intricate prooess, not easily understood or attained by the ordinary mortal. Such was not the case. Irrigation was simple, and might bo accomplished by any intelligent farmer or orchardist. Irrigation reclaimed arid wastes, made a country prosperous by ensuring full crops every season, improved the land at each submergence, and by increasing the productive capacity of the_ soil brought about closer settlement —a condition that should be the chief aim of administration, for the future prosperity of a country dopended upon its productiveness. There was a paddock in Central Otago which had for over 20 years produced consecutive crops of oats, the yield last year being 63 bushels to the acre, which indicated that the fertility of the soil was keeping up remarkably well without rest or rotation. No fertilisers _of any kind had been used; the result beingproduced by irrigation alone. There was no doubt that there was much truth in the argument that many irrigating waters contained largo quantities of mineral fertilising elements in solution. Tho boundary between irrigation operations and purely agricultural processes employed in cultivation was -very indefinite. It could be truly said that the methods of cultivation had far more influence in determining the best course of irrigation than the climate of the locality or the characteristics of the soil. It needed no stretch of imagination to conceive that a complete irrigation scheme required the collaboration of an engineer, an agriculturalist, and last, but not least, a lawyer; the first to design and construct the hydraulic works, the second to determine the system of irrigation, and the third to put in motion the machinery of the undertaking. Irrigation might bo classed under two headings—perennial and flood or inundation. Irrigation might bo described as perennial where water was applied to land under crop at a fairly equable rate during the whole season of crop-growing, and that was the type of irrigation it was proposed to discuss. When the larger proportion of the irrigation water was secured by deeply flooding the land, and tho crop growth was wholly or partially sustained by the moisture thus stored up in tho soil, the term "flood or inundation irrigation" was employed. Different types of crops required different quantities of water for successful irrigation, while the character of the subsoil was a dominant factor. Reference was made to the acquiring of water rights, and the Cromwell Company's irrigation project was then briefly dealt with. There were, in tho vicinity of Cromwell, some 4500 acres irrigable, and this was at present a dreary, waste. Tho problem before the company was the reclamation of this arid waste by applying in a. scientific manner the additional amount of water required to make up tho deficiency in rainfall. Ho (Mr Williams) had recommended tho adoption of a hydropumping system, obtaining sufficient energy hydraulically to lift tho required irrigating water. It had 'often boon stated that in Central Otago, where the land wa?_ of a sanely nature, with a gravel subsoil, it was impossible to convey a head of water within a reasonable period over 100 acres of % land. Tho lecturer was inclined to agree with the statement, but assorted that it was not his intention to try to do it. Ho could supply a man continuously with one-fifth of a head for 180 clays, but no crops required continuous watering. In fact, it would be highly detrimental to them, and three, or at most four, waterings nor season would he ample. The lecturer then proceeded to deal with tho particulars of tho subject—namely "The Cromwell Developing Company's Scheme." and in doing so used the lantern slides before referred to. At the conclusion of the address Mr George Simpson, who presided, expressed tho indebtedness of those present to Mr Williams for his interesting paper, and a vote of thanks was accorded by acclamation.