Slides from a presentation February 17, 2011 at the Wyoming Groundskeepers and Growers Association annual conference.

1. Interpreting WaterQuality Reports Karen L. Panter, Ph.D., C.P.H. Horticulture and Specialty Crops Department of Plant Sciences

2. How do we measure water quality? Alkalinity Salinity pH Sodium Adsorption Ratio Specific Ions Suspended Solids

3. Desirable Characteristics EC <0.5 dS pH 5.0 – 7.0 Alkalinity 40 – 100 ppm Nitrate <5 ppm Magnesium <24 ppm Ammonium <5 ppm Phosphorus <5 ppm Potassium <10 ppm Calcium <120 ppm Sulfates < 240 ppm

4. Desirable Characteristics Manganese <2 ppm Iron <5 ppm Boron <0.8 ppm Copper <0.2 ppm Zinc <5 ppm Molybdenum <0.02 ppm Aluminum <5 ppm Sodium <50 ppm SAR <4 Chloride <140 ppm Fluoride <1 ppm

5. Desirable Characteristics 5

6. pH A pH reading is a measurement of the hydrogen ion concentration of a solution 0 most acid to 14 most basic pH = 7 is neutral pH = 5.4 to 7.0 acceptable

7. Salinity Total dissolved solids Measured by electrical conductivity determined by passing a current through the solution and determining its electrical conductance units are millimhos/cm, or decisiemens/meter (dS/m)

8. Salinity Restrictions to use: < 0.25 dS/m None 0.25-0.75 dS/m Moderate 0.75-2.25 dS/m High > 2.26 dS/m Severe Multiply by 700 to convert to ppm TDS Total Dissolved Solids

9. Alkalinity The ability to neutralize acid (meq·L-1) or ppm (upper limits) total carbonates (CO3 ) bicarbonates (HCO3) hardness (Ca + Mg) Restrictions to use (in meq·L-1): < 2 None 2-8.5 Slight to moderate > 8.5 Severe

10. SAR - Sodium Adsorption Ratio Relates sodium to calcium and magnesium levels in water Must be done by water testing laboratory Can lead to deficiencies in calcium and magnesium

11. Sodium Adsorption Ratio High sodium in relation to calcium and magnesium can be detrimental to plant growth SAR should be < 10 Greenhouse < 4 Calcium may precipitate

12. Examples of Real Analyses 12

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33. And now….any questions? 33