10 BULLETIN 419, IT. S. DEPARTMENT OF AGRICTJLTITBE. 



The water system, after it is established, will determine to some 

 extent the arrangement of the beds. A row of hydrants will fix the 

 location of a path, and to facilitate watering at least the transplant 

 beds should be laid out with their long axes at right angles to this 

 path or row. 



OUTFIT. 



WATER SYSTEMS. 



The initial cost of a water system is high, and once a system is 

 installed it can be changed only with considerable difficulty and ex- 

 pense. A satisfactory system will save many hitches and delays and 

 in the end will effect great economy. It is desirable, therefore, to 

 plan carefully before its installation and to have in mind its realty 

 essential and most desirable features. These will be enumerated 

 under the discussion of the different kinds of systems. There are 

 two principal types of s} r stems in use in nursery operations: (1) The 

 irrigation system, and (2) the sprinkling system. 



IRRIGATION SYSTEM. 



In the irrigation system the water is brought to the nursery area 

 either in a ditch or flume which taps a supply at an elevation some- 

 what above that of the nursery, or it may be pumped from a lower 

 level to that of the nursery. It is then distributed to the plants either 

 by means of numerous small ditches from 2 to 3 feet apart having 

 so slight a gradient that the water flows very slowly, or by flooding 

 entire beds. When water is diverted from a stream desirable fea- 

 tures of an irrigation system are a good, substantial dam at the point 

 of diversion of the w 7 ater, a head gate which permits perfect control 

 of the water entering the ditch, and a clay-lined ditch or a flume to 

 convey the water to the nursery. A flume or water pipe is somewhat 

 preferable to an open ditch. The gradient of the main ditch or flume 

 will depend upon the velocity desired and the cross-sectional area of 

 the channel. At the Savenac Nursery the main ditch, which is 

 slightly over a mile in length, has a fall of G feet. The gradient of 

 the small ditches which convey the water to the plants throughout the 

 nursery should not, in heavy soils, exceed 1-J inches, or, in light, 

 porous soils, 3 inches per 100 feet. 



When water is pumped from a low r er level directly to the nursery 

 for irrigation purposes, the prime essential in addition to that of 

 gradient is that there be pumps of sufficient capacity to furnish all 

 the water necessary while the operation is in progress. At the 

 Bessey Nursery three 5-horsepower gasoline engines and centrifugal 

 pumps are used to pump water from the river into a 4-inch main 



