248 TWO METHODS OF FARM IRRIGATION. 



the soil is such that increasing the size of the streams has no effect 

 on the lateral or sideway soakage, then }ou must consider whether 

 it would not be better to irrigate by flooding. At the same time, 

 if the water between the furrows only meets a foot or so below 

 the surface, it may show that the ground is better adapted for 

 trees than for vegetables, etc. 



This system works like a charm when properly arranged ; but 

 the grading of the furrows must be carefully done, and they must 

 he kept clean. If they get blocked with rubbish of any sort, a 

 little dam soon forms, and then you have two or more streams 

 joining which may disarrange the other furrows. It pays you to 

 have your furrows in good order from the start. 



The even feeding of these furrows requires some little care and 

 thought ; for a large number of them must be fed at once, and if 

 you wish to have an easy time, save labour, and not run back 

 every few minutes to see that things are right, you must make a 

 more or less permanent arrangement. It is a common thing for a 

 iDCginner to attempt to let out the water directly from a large 

 canal in a number of small streams to feed the furrows. In a 

 short time some of them have cut down into the bank, and dis- 

 charge so much water that the other furrows get none. He throws 

 in a little mud, a few stones, a piece of old sacking, and, thinking 

 he has made it all right, goes back to his lands. After a while he 

 finds that instead of threads of water there is quite a stream rush- 

 ing down behind him. His patched-up bank has given way again. 

 Makeshifts are no good whatever. Do the thing properly and 

 there will be no trouble. 



With small canals it is possible to arrange for the delivery of 

 water for furrow irrigation by placing sacks, half-filled with earth, 

 along a bank. These must be fixed at such a levefthat when the canal 

 Is blocked the water runs over in a succession of small streams, 

 each one just large enough for your small long furrows. But 

 this method would be classed as a makeshift by manv irrigators. 

 Outlets properly made should be of wood, iron, masonry, or brick- 

 work. Only in small canals can tflcv be permanently fixecl in the 

 banks, and they must be so arranged that, when not in use, they 

 are above the ordinary level of the water in the canal. With large 

 canals, it is necessary to let the water into a sort of long trough or 

 flume, and the trough must be fitted with the outlets to feed the 

 small furrows. 



Many irrigators find that the best results are gained by build- 

 ing a permanent trough or flume below the canal, with openings 

 about one inch large every 3 feet. This trough can be supplied 

 from the canal through a sluice, and the sluice can be set so as to 

 ■discharge just the amount required to supply the trough. When 

 not in use the sluice can be closed. When this is properly arranged 

 small boys can do all the irrigating required. These troughs can 

 be made of almost any material, and can be formed by planks, 

 sheets of iron, or masonry walls along the lower side. 



The beauty of this system is that the water is under absolute 

 •control, and can be used on steep sloping ground bv carrying the 

 furrows on a grade round the face of the hills. The velocity of 

 the water can thus be regulated, instead of rushing down the 



