ii6 



Journal of Agriculture, Victoria. 



[lo Feb., 1911. 



IRRIGATION. 



6'. H. Tolley, Manager, W'yuiia Irrigation Farm. 



{Continued from page 62.) 



Channel Outlets and Head Ditches. 



Upon completion of grading the next step is to provide channel outlets 

 and head ditches for distributing the water. Wherever it is possible make 

 these ditches level, and where otherwise, provide them with regulators so set 

 as to furnish the greatest facilities for securing effective irrigation. The 

 most effective tool for this purpose is the crowder or delver. 



After staking out the posi- 

 tion of a ditch, plough the 

 surface the full width re- 

 quired, and as deeply as 

 possible, leaving a strip of 

 6 inches or 9 inches along 

 the centre untouched, to act 

 as a fulcrum for the furrow 

 run along the course of the 

 very like the mouldboard of 



39. section of crowder drain. 



40. crowder drain improved. 



board of the crowder. The machine is now 

 channel with the wing board (which acts 



a plough) set rather narrow, the furrovv' board running straight along the 

 edge of the unploughed strip. The return trip is made along the other 

 side of the strip. This 

 operation crowds the 

 earth out towards the 

 edge of the ploughing. 

 It is repeated with the 

 wing board set wide 

 enough to crowd the 

 earth out to about the position where the bank is required. It may, or 

 may not, be necessary to repeat the work more than twice ; it depends upon 

 the nature and condition of the soil and must be left to the judgment of 

 the operator. When the loose earth has all been shifted, the bed is again 



ploughed and the 

 strip previously left, 

 broken down. This 

 ploughing need not 

 cover so great a 

 width as at first and 

 should be deepest 

 in the centre. The pitch now on the sides of the channel is sufficient to 

 keep the furrow board running in a fairly straight line; to help it do so, 

 the operator can regulate the tilt of the machine by means of the handle 

 provided, while the draught may also be adjusted so as to keep the nose 

 buried as much as may be found necessary. A repetition of the work 

 described as succeeding the first ploughing is all that is required to com- 

 plete the work. The number of repetitions and the set of the wing board 

 for successive operations may safely be left to the operator, the work 

 naturallv being much less in a free loamy soil than in stiff clay, which 

 breaks uo in lumos. 



crowder drain completed. 



