Water Application Uniformity

One important way to reduce the amount of water applied by nursery irrigation systems is to make certain that water is spread evenly across the growing area.

If your system does not apply water uniformly, the system must be left on longer to make sure that plants in dry areas get enough water. Nonuniform water application results in distinct patterns of water-logging, reduced plant vigor, and greater Phytophthora disease problems.

An irrigation system's water distribution is affected by:

  • Wind speed and direction
  • Water pressure
  • Sprinkler spacing and height
  • Nozzle selection
  • Slope of the land

Test water application uniformity regularly: in late spring when the system goes on, again in mid-summer, and in late summer.

  • Set up a grid pattern of catch-cans
  • Operate the system for a period of time under normal conditions
  • Measure the volume of water collected in each catch-can

Irrigation industry guidelines can help you evaluate water distribution uniformity. Improving a sprinkler system's uniformity can reduce water use by as much as 40%. An irrigation system rated excellent will lower operational costs, such as pumping costs, and helps to discourage Phytophthora disease.

For details, see Determining the Application Uniformity of an Irrigation System by R. Regan, attached below.