Farm and Garden.

Alexandra Herald and Central Otago Gazette, Issue 389, 22 October 1903, Page 7

Farm and Garden.

—__*, ORIGINAL ARTICLES. IRRIGATION. SjiKjjftOW the recent disastrous drought ilwlr m va " oas P artß o£ Australasia 3fk>|f£ has forced maay people to con- . sider the necessity of irrigation, and whenever it has been introduced the rapid change that has taken place is very remarkable, and indicates prosperity where previously were poverty and distress, caused by barreness of the soil in consequence of the drought. In those parts where irrigation has.been introduced, the luxuriant vegetation iB greatly in contrast to those portions not under . irrigation. But in any jof the states, where ever agricultural pursuits are carried on, irrigation renders farmers independent when they possess that in* valuable adjunct to-the soil, an abundant supply of water, and at all times under control. Occasionally there are streams of water from, which channels may be cut, with a system of laterals round and about the crops; in many other cases by boring some few feet below the surface an abundant supply of good water has been obtained, which by means of the ordinary irrigation pumps may be lifted and distributed into the virious channels previously prepared for that purpose. The average amount of fall per mile of some large streams does not exceed two feet, and frequently much less; say two feet, then the grade in a channel from that source should be only twenty inches per mile j therefore under those circumstances a gain of more than eight feet per mile in elevation is possible. It will be perceived that only a few miles of watercourse following this principle will be required to convey the water from the river level to the higher parts of the locality, at which elevation the laterals or individual channels may tap it and conyey the water down the slope toward the river again, The main water channel should not be mora thaa two feet in depth, as easy access to the water all along the line is an important matter. Another important point in practical ,; utility is that the water channel should, in engineering language, be a contour line—that is, that it should follow the windings of the ridges, instead of cutting and filling across the little hills and hollows encountered. The reason for that is greater convenience in tapping the supply and greater safety. In the contour method the water has the natural earth for its banks, and is, or should be, wholly below the level of the surface, If one follows the bee line idea, there are numerous small depressions to be dealt with, either by flumes or fills, and experience has shown that neither of these ie as stable or secure as might be desired. The earth fill is made like a railway fill with the water. channel hollowed out of the middle, and conveys, to the mind, soft earth, or mud whenever the water is ' j admitted with a tendency to seek ita> ti lowest level. That objection lessens [ v when the water channel consists of pud- _ died clay. The more technical questions as to the best place to tap a river, or the i best place to get rid of shifting flanda and so forth, should be referred to a competent" engineer, remembering that a good rail-, way'engineer is not necessarily a good hydraulic engineer. The amount of water. . required to irrigate an acre of land is one' inch, that being the amount of water flowing continuously from the opening to the close of the season through an opening one-inch tquire under a four inch ; pressure; that is, the water standing four ! inches above the opening from which it is taken. This estimate is for an arid region where there is little rainfall. But in any state is carried on the most truly independent of all farmers is he who, owning the soil, owns also that invaluable adjunct to that soil—an abundant Bupply of water from an un. failing stream close at hand, and at all times under his control. ■ Such a water right becomes by use appertinent to the aoil whereon it is used, and may not only be a rich blessing to himsel, but may be davised as a precious legac j to hiß children. Doubtless there are many streams of water that could be so used for Hub purpose by the intelligent irrigators.