Full Product Manual

soil types, continued
—loam soil having a mixture of the different grades of sand, silt and clay in such proportion th
a
none of the characteristics predominate; it is mellow with a somewhat gritty feel, and
when moist is slightly plastic. Squeezed when dry, it will form a cast that will bear
careful handling; the cast formed by squeezing the moist soil can be handled quite freel
y
without breaking.
—sand a loose and single-grained soil; the individual grains can easily be seen or felt. Squeeze
d
in the hand when dry, it will fall apart when pressure is released. Squeezed when moi
s
it will form a cast but will crumble when touched.
—sandy loam a soil containing much sand, but which has enough silt and clay to make it somewhat
cohesive; the individual sand grains can readily be seen and felt. Squeezed when dry, it
will form a cast that will readily fall apart, but if squeezed when moist, a cast can be
formed that will bear careful handling without breaking.
—silt loam a soil having a moderate amount of the fine grades of sand and only a small amount of
clay, over half of the particles being of the size called "silt." When dry, it may appear
cloddy, but the lumps can be readily broken. When pulverized, it feels smooth, soft, and
floury. When wet, the soil readily runs together. Either dry or moist, it will form casts
that can be freely handled without breaking; however, when moistened and squeezed
between thumb and finger, it will not "ribbon" but will be broken in appearance.
spaghetti tubing See 1/4" distribution tubing.
system efficiency a factor that denotes how efficient the irrigation system is at applying water. When
water is discharged from the system, only a certain percentage will reach the plant roo
t
zone and be available for consumption. The percentage of water that reaches the plant
and is available equals system efficiency. It is impossible to reach a 100% eficiency.
valve a device that opens and closes to allow pressurized water to flow through pipes.
valve box an underground enclosure that protects valves from moisture and other damage.
valve zone a group of sprinklers that are controlled by a single valve (see hydrozone).
water source pressurized water in a city main line or water pumped from a well, lake or pond.
watering window the amount of time available to water in any one period.
wetting pattern the area of the ground that is wet just after irrigation; an ideal wetting pattern covers t
h
root zone of the plant without leaving a puddle.
Xeriscape a planting scheme that groups plants with the same irrigation requirements together.
Page 98 Appendix E
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