14 



CHAPTER IV. 



LAYING OUT THE LAND FOE WATERING. 

 IRRIGATION CHANNELS. 



After the land has been grubbed, graded, and 

 ploughed, the next thing is to have the irrigation 

 channels put in from which the land is to be watered. 

 The channels are usually made from lime or cement 

 concrete, but irrigation by means of reinforced 

 cement piping has within late years been introduced 

 and given satisfactory results. 



The greatest care should be exercised as to where 

 the channels are put down. Upon the position of 

 the channels depends the length of the rows of trees 

 to be watered. Experience has shown that in loose, 

 sandy loam rows 5 chains in length are long enough, 

 and that on no consideration should rows over six 

 chains long be watered in one section on this class 

 of land. 



As on the loose, sandy rises, of which the irrigation 

 settlements chiefly consist, the furrow system of 

 irrigation is practically the only one that is used it fol- 

 lows that the water is flowing for a considerable time 

 past the first trees of a row before it reaches the last 

 one, therefore, the longer the rows are, the longer will 

 the water take to reach the end. On very long rows 

 the first tree will have had too much water before the 

 last tree will have had enough, and the top of the 

 land will in time become water-logged, to the injury 

 of the trees. In any case, the surplus water will soak 

 down the slopes along the sub-soil, and should this 

 in any case come close to the surface of the ground, 



