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Art. XXV. — On Irrigation as applied to the growth o/New Zealand Flax. 

 By J. C. Crawford, F.G.S. 



[Bead before the Wellington Philosophical Society, August 14, 1869.] 



There is no country in the world which rejoices in more numerous sparkling 

 streams than New Zealand, and in this respect it contrasts remarkably with 

 the neighbouring territory of Australia ; but the rivers are seldom navigable 

 to any distance from the coast, and their waters generally reach the sea 

 without proving of more utility to mankind, than for the common supply of 

 liquid for daily consumption. 



There are two modes by which the streams may be made useful to 

 mankind. 



1. By forming reservoirs of power. 



2. By fertilizing the soil by irrigation. 



It is my intention at present to consider the latter point only. 



In Europe two systems of irrigation are adopted. In the warm climates 

 of the Mediterranean basin, water is conveyed to the fields under crop, for the 

 simple purpose of providing the necessary moisture. 



In the colder latitudes of England, France, and Germany, water-meadows 

 are put under irrigation during the winter season, at a time when, primd facie, 

 one might suppose that the soil was sufficiently moist. These meadows are laid 

 out on two plans : on level ground they are formed into ridges and furrows — 

 the water running on to the ground along conduits on the top of the ridges ; 

 then flowing gently over both sides, is carried away by the drain in the 

 furrow. To lay off land carefully in this manner is expensive, but the returns 

 are very great. On uneven ground the catch meadow system is adopted. 

 Advantage is taken of the inequalities of the ground to run the water as 

 evenly as possible over the surface, and with proper skill and judgment this 

 object is often attained at slight outlay. 



It is a remarkable fact, that although the fertility of water meadows is 

 vastly increased by an admixture of manure with the water, yet that water, 

 containing apparently no foreign element of fertility, is capable, when applied 

 to the soil, of enabling it to return, year after year, heavy crops of hay and 

 grass. This is a point which science has not, as yet, thoroughly explained. 



As examples of irrigation I will mention the water meadows near 

 Edinburgh, which are irrigated by strong town sewage. These meadows 

 produce frequent heavy crops of grass, and ai'e said to make a return of from 

 £20 to £60 per annum, according to distance from the fertilizing sources, and 

 the nature of the soil. In "Wiltshire, Berkshire, and many other counties in 

 the south of England, the return from water meadows, irrigated without 

 sewage, is very large, and I think that, at a moderate estimate, a return of 

 from £5 to £7 per acre may be considered the average. 



The meadows provide early grass for the ewes and lambs in spring, a 

 heavy cut of hay in summer, and an aftermath in autumn. 



From my own experience, in a cold district in Scotland, I may state, that 

 after throwing the drainage water from the upper part of my property, so as to 

 irrigate some fields on the lower part, I have obtained, ever since, an increased 

 return, of some 75 percent, from the irrigated portion, over the previous rental. 



In New Zealand, and in no part of the country more than in the 

 Province of Wellington, there are facilities for irrigation possessed by few 

 other countries. It would be absurd to advise expensive modes of laying off 

 land for irrigation, in the present sparse state of the population of the colony ; 

 but if it should appear that large tracts of country may be irrigated at 

 moderate expense, for the purpose of developing a staple export, the subject is 

 at least worth enquiry. The export of the fibre of the Phormium tenax has 



