With the rising Electrical Conductivity (EC) level in the past several years affecting irrigation water for a variety of crops, some helpful resources are listed below. For specific questions, please do not hesitate to reach out to your local extension agent.

Testing water:

There is an EC meter available at the Chowan and Perquimans extension offices. Please bring your water sample in a mason jar or water bottle for testing. Instructions on how to use the meter are available at the county offices.

General rule of thumb:

You should consider limiting irrigation for areas with source water that is greater than 0.45 ppt (parts per trillion). If salinity values are in excess of 0.45 ppt, check the salinity tolerance of the crop before deciding to irrigate. For most of our crops, you should consider not irrigating over 2.0 parts per thousand unless the crop is about to die and you need rescue irrigation.

Additional testing:

For samples with an EC reading of 0.45 ppt and above, we recommend sending a water sample to the NCDA lab for additional testing. NCDA states that water with Sodium and Chloride levels >70 ppm can cause toxicity when absorbed by foliage; Cl levels > 70 ppm can cause salt damage to the roots, resulting in the plant being unable to take up water or nutrients.

Visual symptoms:

Visual symptoms of Na and Cl toxicity include wilting, leaf edge burn, leaf necrosis, and leaf abscission; however, yield loss may occur even without seeing physical symptoms. Sodium can also cause permeability issues in the soil. Both of the elements can be harmful to plants by foliar absorption (overhead irrigation) and root absorption from the soil solution.

The best solution for managing water with high levels of Na and Cl is to dilute it with another irrigation water source (shallow well) if possible, or avoid irrigating.