655 EXPERIUEXTAL FARM^ 



V 



7 GEORGE V, A. 1917 

 IRRIGATION FOR THE VEGETABLE GROWER. 



A system of overhead irrigation was installed at the Central Farm during the season 

 of 1915. The whole vegetable area of the Horticultural Division, comprising some 

 6-8 acres, was completely equipped with the plant. Although no information is avail- 

 able regarding the benefits to be derived from irrigation, some suggestions are here 

 presented. 



Owing to the lateness of the season before the installation was completed, it was 

 impossible to conduct any comparative test of the merits or demerits of irrigation, 

 although the plant was successfully operated several times during the summer. 



METHOD OF INSTALLATION. 



The whole area under irrigation comprises 6-8 acres, ajid the system is so arranged 

 that the whole area can be irrigated at one time. This demands a water supply of 320 

 gallons per minute after all fricticin heads have been deducted. As the field is located 

 1.600 feet from the source of water supply, a main pipe line of 1,600 feet of 4-inch 

 galvanized iron pipe was the first step involved. Galvanized pipe was decide'd upon for 

 underground work on account of its longer life than ordinary black iron pipe. Cast-iron 

 pipe would, of course, have been better still, but, owing to its high cost, it was not 

 considered. Had it been considered advisable to operate only one-third or one half the 

 system at one time, the main pipe line could have been reduced to a 2-inch or 2^-inch 

 pipe, with a consequent reduction in the cost of installation. 



In addition to the main pipe line, another underground line was installed through 

 the centre of the field. This is known as the feeder line, and every 50 feet along this 

 line, l:^-ineh risei^s or uprights are attached. These risers supply the water for the 

 nozzle lines. This feeder line is 775 feet in length and consists of 400 feet 3-inch pipe, 

 225 feet 2i-inch and 150 feet 2-inch pipe, the 3-inch pipe joining directly to the 4-inch 

 main line. The underground system is not put below frost line at every point. From 

 the water supply to the field the 4-inch line was made to run down hill a little and was 

 put about two feet below the surface. Drain cocks were installed at both ends of the 

 line, so that no water would be left in the pipes over winter. The feeder line, owing to 

 a sharp hill in the field, slopes in two directions, and is drained from both ends. Care 

 was taken, of course, that no pockets remained in the system to hold water over winter. 

 The overhead system is installed in as permanent a manner as possible, that is, the 

 nozzle lines are carried on galvanized iron posts set in cement, and are carried to a 

 height of seven feet over the highest hillock. This permits a team of horses to work 

 under the system of nozzle lines, without interference. These nozzle lines are directly 

 attached to the risers and radiate from both sides. Each line is a separate ilnit in itself, 

 that is to say, each line has its own turning union and shut-off and can be turned in 

 any direction or shut off or put on without interfering in any way with the other lines. 

 This makes 32 separate working units in the whole system. Each separate nozzle line 

 is 190 feet long and consists of 60 feet of 1-inch and 130 feet of f-inch galvanized pipe. 

 These overhead lines are supported by 1-inch galvanized iron posts placed every 15 

 feet and set in cement. The nozzle lines are 50 feet apart, so that by turning each line 

 over, it is made to cover a 50-foot space, as the spray reaches 25 feet on each side of 

 the nozzle line. The Skinner nozzles are placed every four feet on the nozzle lines and 

 are in a perfectly level and straight row. This system is, of course, the most permanent 

 and hence the most expensive method of installation. For a market gardener, desiring 

 a somewhat cheaper installation, the overhead pipe lines could be carried on wooden 

 posts resting on blocks of wood, or driven deeply into the ground. This would reduce 

 the cost considerably. Another point is that already referred to. namely, that a smaller 

 area could be installed at a much lower cost per acre, on account of the smaller feed 

 line necessary. 



Ottawa. 



