1. Irrigation Water Quality & Influence on Crop Production Sam Taylor, March 2016

2. Crop Tolerance to Salinity Many factors affect crop tolerance – Climate – Soil Type – Irrigation Method & Management – Crop Type / Rootstock

3. Water Quality Factors Electrical Conductivity – Measures total salts (includes calcium, potassium, magnesium, sodium, bicarbonate, nitrogen, phosphorus, iron, sulphur -Sodium concentration is the killer… -Affects plants -Alters soil structure

4. Measuring Salinity Conversions between units can be confusing EC, ms/cm, dS/m or u S/cm 1 dS/cm = 1000EC or approx 640 mg/kg (ppm) Scheme looking to deliver water < 800 u S/cm (500 mg/kg) in a dry season

5. Water Quality & Yield Loss CropNil reduction (dS/m)10% Reduction (dS/m) Apples0.71.0 Avocadoes0.81.0 Barley5.36.7 Broccoli1.92.6 Maize1.11.7 Perennial Ryegrass3.74.6 Plums1.01.4 Potatoes1.11.7 Raspberry0.71.0 Strawberry0.70.9 Sugar Beet4.75.8 Walnut1.11.6

6. Water Quality & Yield Loss

7. Relative values Sea Water – 50,000 EC units Wellington Water(Dec’15) - >1200 ppm Myalup – 800 – 1500 ppm TDS

8. Flow Rate or Volume Volume = total requirement over season Flow rate = high volume in short period Consider – Seasonal crop requirement – On farm storage capacity

9. How much water do I need?

10. How Much water do I need?

11. How much water do I need?

12. Summer or Winter Water? Crop demand On farm storage capacity – Capital cost of new storage vs summer rights Evaporation Losses Quality vs Quantity