Irrigation water quality

Irrigation water quality

I used these slides for a presentation about irrigation water quality at the Sustainable Turfgrass Management in Asia 2017 conference. I then showed various calculations of the daily soil water balance.

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Micah Woods

March 08, 2017
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Transcript

  1. 1.

    Irrigation water quality Micah Woods 8 March 2017 Chief Scientist

    | Asian Turfgrass Center www.asianturfgrass.com
  2. 11.

    Salinity is measured in two ways Total dissolved solids By

    evaporating the water, and measuring what remains, one gets total dissolved solids (TDS), reported as mg/L, or ppm.
  3. 12.

    Salinity is measured in two ways Electrical conductivity When there

    is more salt in the water, it can conduct more electricity. The electrical conductivity (ECw ) is in units of dS/m.
  4. 14.
  5. 18.

    This is called a leaching fraction 2 step process First,

    calculate the leaching requirement (LR). Second, calculate the quantity of water to apply. Let's imagine we have a water with a TDS of 1,500 ppm. And we expect the grass to use (ETc ) 4 mm. How much water is required for irrigation?
  6. 20.

    Using the leaching requirement After we have the LR, then

    we calculate the quantity of water to apply as: irrigation = ETc 1 − LR
  7. 27.

    If there is too much sodium in the irrigation water,

    the sodium causes deflocculation of the soil clay particles. This is not a problem on sand rootzones.
  8. 41.

    Know three numbers 1. The volumetric water content (VWC) at

    field capacity 2. The VWC at the wilting point
  9. 42.

    Know three numbers 1. The volumetric water content (VWC) at

    field capacity 2. The VWC at the wilting point 3. The VWC now