What irrigation-related issue can arise when using high-salinity reclaimed water, and how can it be mitigated?

• A. Salt buildup in soil stressing plants; mitigate with flushing, selecting salt-tolerant species, and adjusting irrigation frequency.
• B. Increased soil moisture retention reducing drainage; mitigate by aerating soil.
• C. Decreased nutrient availability due to low salinity; mitigate by applying more fertilizer.
• D. No impact on soil or plants when using reclaimed water.

Answer: (A)

High-salinity reclaimed water introduces more dissolved salts into the root zone, causing salt buildup in the soil that stresses plants. The salts raise the soil’s electrical conductivity, creating osmotic stress that makes it harder for roots to take up water, and certain ions can become toxic at high levels, reducing growth and causing leaf burn. To mitigate this, flush the soil with ample clean water to leach salts beyond the root zone and ensure there is good drainage so salts don’t accumulate. Adjust irrigation frequency and volume to maintain a leaching fraction that continually moves salts down and out of the root zone, while avoiding waterlogging. Selecting salt-tolerant species or varieties can also help plants cope with the higher salinity. Regularly monitor soil and irrigation water salinity (EC) to guide management decisions and keep salt buildup in check.