Soluble nutrients move by
water. Water is applied to containers by an irrigation system. The irrigation
system must be functioning correctly for the water to be delivered efficiently.
An understanding of water flow, pressure, friction and power will help you evaluate a system and prepare recommendations for improvements. There
is an opportunity to achieve energy and water conservation, and improvement
of the system. You must be able to determine the flow rate of water
through nozzles or emitters or water meter, to calculate the amount of water
Non-uniform pressures in
an irrigation system cause non-uniform application of water. Pipes that are
too small, in the sense that the water must flow "fast" to supply the demand,
have a high pressure or energy loss that is caused by the friction of water
rubbing against the pipe walls. An increase in water velocity in a pipe causes
more friction that results in a loss of usable pressure in the system.
The movement of water through
an irrigation system is described by hydraulic principles. Terms such as flow,
pipe cross-sectional area, water velocity, water pressure, friction loss, and
power are described here to help in understanding, evaluating, and designing
an irrigation system.
Several exercises will be included for self-study and
review of the concepts presented in this section.