IRRIGATION IN H.B.

Hawke's Bay Herald-Tribune, Volume 81, Issue 63, 7 December 1937, Page 7

IRRIGATION IN H.B.

Address to Napier Rotarians CHEAP & EFFECTIVE METHODS Irrigation in general, and its possible application in Hawke ;s Bay in particular, was the subject of an address to the Napier Botary Club yesterday by Mr J. E. Marks, A.M. .Inst. C.E., of Auckland. Most people had some hazy idea of irrigation, which they associated in their minds with intensive farming on a small area, with the water distributed in furrows between the rows of plants, Mr Marks said, but it was his aim to show the benefit of irrigation under less intensive conditions, particularly in regard to sheepfarming. Mr Marks said that he had been closely associated with irrigation in the South Island. The Hawke 's Bay district had from time to timo in the past flirted with the idea of irrigation, Mr Marks went on. History showed that the lands first irrigated in most conntrie3 had been arid or semi-arid on accaunt of the fact. that they were useless otherwise, hut, because such land was practically devoid of humus on account of there having been no vegetation there, it was often up to ten years before full productivity was reached. Lands that suffered from seasonal drought were not uSually taken in hand untii later, though on these lands one could achieve immediate results for a small capital outlay. In this district there must be ample opportunity for that sort of irrigation. Mr Marks did n'ot go into the engineering problems of obtaining the main supply of water, eseept to say that c[uite often it could be obtained on the runs, but confined himself to dealing with methods of distributing it over the land. 3h hilly country^, he said, practically the only way to apply the water was the contour method, in which furrows were plougbed xound the hillsides at intervals in height. The water was then run into the upper oue and allpwed to ooze down the hillside, spreading round the furrows aud flowing down to the next level. This method was very cheap in the first instance, but requiied a lot of maintenance work, On foot,hill country with a general falJ, the I method most commonly used was to run ! the water downfield in parallel ditches, dammed at intervals .to make it spread. The cheapest form of application on flat or nearly fiat country was to form low ridges, about six feet wide at the base and about six inches high and

about ten chains long with level pieces in betweeh, thus confining the water to floods. Once these ridges had been made they would be permanent and would not interfere with oultiva^ion. A large flow could be let into each section from the main supply and allowed to seep over the area. The nest questions to be considered were how much water should be used and how often should it be applied. These problems could be answered by the study of various soils for holding capacity and xate of absorption. The scheme outlined represented field^. irrigation at its very cheapest with the minimum of maintenance expenditure. The speaker coneluded his address by advising his hearers to givo serious though t and encouragement to any irrigation seliemos which might be put forward in this district.