8 Feb., 1908.] 



Preparing Land for Irrigation. 



In irrigating, these channels are dammed at distances varying from i 

 to 3 chains by placing a temporary dam in the channel which stops the 

 flow and causes it to run over the bank. The temporarv dam mav be 



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2. Canvas Dam. 



of canvas (Fig. 2), or it may b-e of earth made with a dammer (Fig. 3), 

 which is run through the channel when it is made and after each subse- 

 quent irrigation, or these dams may be of manure faced with earth. If 

 tt>e lucerne has been drilled in the direction of the steepest slope it will 

 help to secure an equal distribution. The water is allowed to run until 

 the surface soil is thoroughly saturated, any excess which runs off being 

 caught by the next lower lateral. The evenness of the distribution of 

 water bv this method depends on the freedom of the land from knolls ; 

 on the even flow over the top of the ditch ; and on the skill of the irrigator 

 in directing water to the highest parts of the field. 



Fig. 3. Dammer used in Cleaning and Damming Field Channels. 



This method of irrigating is well suited to grain and forage plants 

 where the soil does not bake, but it is difficult to secure an even spread 

 of water and the work of distributing is expensive and laborious. This 

 has led to the use of checks where the land has a low enough grade to 

 admit of their adoption. 



2. Flooding in Contour Checks. — Preparing the field for flooding 

 by checks consists in throwing up low levees on approximate contour lines 

 with cross levees at intervals to limit the area of the checks. This 

 method is very well suited to the land around Kerang and in the Goulburn 

 Valley, in both of which places the slopes are gentle, ranging from 9 inches 

 to 4 feet per mile. 



