One or more of the following practices should be implemented if saline or sodic irrigation water
is used for irrigation.
- Provide adequate internal drainage. If a hardpan or other barriers restrict the movement
of water through the soil profile, irrigation water with a SAR greater than 8 or an ECw
greater than 1.50 – 2.00 mmhos/cm should not be used unless proper internal drainage
can be provided.
- Meet the necessary leaching requirement depending on crop and salinity of irrigation
water (ECw). Proper leaching reduces the accumulation of soluble salts and sodium in
the soil. The leaching requirement can be calculated from water test results and
tolerance levels of specific crops.
- Do not allow the soil profile to become less than 50% to 75% of its water holding
capacity during the growing season. Salt toxicity to crops increases as soil moisture
- Monitor the ECe and Exchangeable Sodium Percentage (ESP) of soils annually when
irrigation water high in soluble salts and sodium is applied to soils. When monitoring
these soil parameters, collect soil samples at 12-inch intervals to a depth of 36 inches.
- When reclamation of sodic soil conditions is necessary, gypsum should be broadcast
prior to planting and thoroughly incorporated into the soil. The ESP concentration
should be than 8%. The gypsum requirement should be based on the soil test. If the
soil contains free lime, elemental sulfur (Agri-sul) may be broadcast and incorporated at
a rate of 20% of the gypsum application rate.
- Saline or sodic irrigation water can be blended with good quality irrigation water to
reduce the quantity of salts and sodium applied to the soil. If blended water is applied,
monitor salt and sodium accumulations annually by soil testing.
- Assuming normal concentrations of soluble salts and exchangeable sodium are present
in soil, the maximum amount of soluble salts and sodium that should be applied to soil
annually from the application of irrigation water is 4000 lbs salt/acre and 500 lbs
Na/acre. When applying irrigation water high in soluble salts, do not allow the ECe to
exceed the guideline for the crop to be grown. To maintain good water infiltration and
percolation, the concentration of exchangeable sodium should not exceed 300 ppm and
the ESP is should be less than 8%.