10 BULLETIN 479, TJ. S. DEPARTMENT OF AGRICULTURE. 
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 really 
essential and most desirable features. These will be enumerated 
under the discussion of the different kinds of systems. There are 
two principal types of systems 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 water, 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 6 feet. The gradient of 
the small ditches which convey the water to the plants throughout the 
nursery should not, in heavy soils, exceed 1J inches, or, in light, 
porous soils, 3 inches per 100 feet. 
When water is pumped from a lower 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 
