- Does the salt concentration (ECw) pose a potential problem (osmotic effects)?
| Degree of Growth or Yield Reduction | ||||
| Crop | Unit | None | Increasing | Severe |
| Almond, Walnut & Prune | dS/m | < 1.1 | 1.1 - 3.2 | > 3.2 |
| Pistachio | dS/m | < 4.0 | 4.0 - 8.0 | > 8.0 |
- Are there specific elements (B, Cl, and Na) that could accumulate in the tree or soil to potentially toxic levels?
| Degree of Growth or Yield Reduction | |||||
| Element | Unit | Crop | None | Increasing | Severe |
| B (boron) | mg/l (ppm) | Almond, Walnut, & Prune | <0.5 | 0.5 - 3.0 | >3.0 |
| Pistachio | <4.0 | 4.0 - 10 | >10.0 | ||
| Cl (chloride) | meq/l | Almond, Walnut, & Prune | <4.0 | 4.0 - 10 | >10.0 |
| Pistachio | <20.0 | 20 - 40 | >40.0 | ||
| Na (sodium) | SAR (none) | Almond, Walnut, & Prune | <3.0 | 3.0 - 9.0 | >9.0 |
| Pistachio | <5.0 | 5.0 - 10 | >10.0 | ||
| Na (sodium) | meq/l | Almond, Walnut, & Prune | <4.0 | 4.0 - 7.0 | >7.0 |
| Pistachio | <20.0 | 20 - 40 | >40.0 |
- Could the water chemistry reduce soil tilth, porosity, and cause slower water infiltration rates?
| Potential of Water Infiltration Problems Developing | ||||
| Lab Information | Unit | Unlikely | Increasing Likelihood | Likely |
| Ratio of SAR/ECw | ratio | <5.0 | 5.0- 10.0 | >10 |
| Ratio Ca/Mg | ratio | < 4.0 | 2.0- 1.0 | <1.0 |
- Could the water chemistry be prone to plugging drip emitters, microsprinklers, or filters and reduce irrigation distribution uniformity?
| Potential for Plugging Problems Developing | ||||
| Lab Information | Unit | Unlikely | Increasing Likelihood | Likely |
| ECw | dS/m | <0.8 | 0.8 to 3.0 | >3.0 |
| HCO3+CO3 | meq/l | <2.0 | 2.0 - 4.0 | >4.0 |
| Mn (manganese) | mg/l | <0.1 | 0.1 - 1.5 | >1.5 |
| Fe (iron) | mg/l | <0.2 | 0.1 - 1.5 | >1.5 |
- How much nitrate-nitrogen is in an irrigation water supply?
If lab reports NO3-N, then:
NO3-N (mg/l, ppm) x 2.7 = lbs N per acre-foot of water
If lab reports NO3, then:
NO3 (mb/l, ppm) x 0.6 = lbs N per acre-foot of water
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