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Irrigation


Eco/Mobile Lab Program

A major part of any irrigation management is determining irrigation dates and how much water should be applied. This decision-making process is referred to as irrigation scheduling.

Successful irrigation scheduling depends on the performance of an irrigation system. In particular, it depends on the uniformity with which water is applied across the field, distribution uniformity, and by extension the efficiency of the irrigation system. The farmer or manager must therefore know the performance of the irrigation system.

Lab Evaluations

Mobile Irrigation Laboratories evaluate the performance of irrigation systems. The laboratories measure water application rates and system distribution uniformity and give recommendations for irrigation system improvement, if necessary.

DWR is attempting to expand the mobile lab service to small farms and landscape water users. Increasing uniformity, decreasing over-application of water, and reducing runoff saves water to help sustain California's economic predominance. Education is the key to management of water resources and Mobile Labs can help in that education.

Types of Irrigation Systems Evaluated

  • Flood/Furrow - Advance and recession times, infiltration uniformity, runoff potential and pump efficiency.
    • Furrow
    • Border Strip
    • Level Basin
    • Diked Furrow
    • Cycle Surge

  • Sprinklers - Field pressure uniformity, catch can evaluation for uniformity, energy input, runoff potential and pump efficiency.
    • Portable Move
    • Wheel Line o Solid Set
    • Center Pivots
    • Lateral Move
    • LEPA

  • Micro/drip - Emitter uniformity, system maintenance evaluation, energy input, and pump efficiency.
    • Drip Line
    • Drip Tape
    • Micro Spray
    • Micro Spinner

  • Pump Plant Efficiency
    • Energy input
    • Pumping depth, gallons per minute, discharge pressure.

System Evaluation

Sprinkler Evaluation:

The Mobile Labs perform field evaluation of the sprinkler systems during a normal application of water. The lab will need a few moments of the irrigator's time for an interview to learn about management decisions and irrigation scheduling.

The highly trained team of technicians will inspect the equipment and make notes of the system equipment and any oblivious maintenance issues, such as mismatched heads/nozzles general installation of pump station, filters, valves and main line. They will make general notes on the classification of soil type and topography of the field.

The lab technician will lay out catch cans to measure the irrigation application amounts at various points in the field. After irrigation set, the catchments will be collected, measured and recorded, and distribution uniformity calculated.

Irrigation Distribution Uniformity: defined as the application in the lowest one-quarter of the field divided by the average application across the field.

The general performance will determine the amount of water applied during the normal irrigation.

Distribution Uniformity:

Average Lowest Quarter Catchments

DU =________________________________

Average Catchment

Drip:

The Mobile Lab comes out to perform field evaluation of the drip/micro systems during a normal application of water. The lab will need a few moments of the irrigator's time for an interview to learn about management decisions and irrigation scheduling.

The highly trained team of technicians will inspect the equipment and make notes of the system equipment and any oblivious maintenance issues, such as mismatched drip emitters/nozzle jets, general installation of pump station, filters, valves and main line. They will make general notes on the classification of soil type and topography of the field.

The lab will measure and carefully record emitter emission at a multitude of locations in the field. These measurements are used to calculate the emission uniformity of the field.

Irrigation Emission Uniformity: defined as the application in the lowest quarter of the field divided by the average application across the field.

The general performance will determine the amount of water applied during the normal irrigation.

The EU evaluation will help make irrigation decisions based on the lowest water application area.

Drip systems apply water to a smaller area than, say, sprinkler or flood irrigation. When the amount of water applied is calculated based on the same assumptions as sprinklers or flood irrigation (tree or row spacing), a greater amount of water may penetrate below the root zone. The wetted perimeter needs to be considered to avoid water loss beyond the root zone.

Benefits of System Evaluation
Improving the performance of your irrigation system has several benefits:
  • Increased application efficiency
  • Increased yields
  • Increased profits
  • Improved water quality
  • Decreased amount of water applied
  • Decreased energy usage
  • Decreased nutrient leaching
  • Decreased tail water runoff