Management of Salt-Affected Soils - Practices of Irrigation and On-farm Water Management - page 302

The following approaches may be adopted to ameliorate the salinity effect:

• Removing surface crust/scraping

• Controlling saline water

• Hydraulic/engineering practices (e.g., salt leaching, drainage, artificial recharge)

• Chemical practices (e.g., reclamation/treatment of saline soil)

• Irrigation and water management practices

• Physical methods

• Retardation of saline water intrusion

• Biological reduction of salts

• Increasing water use of annual crops and pastures

• Other management practices

Salinity avoidance, mulching/crop residue application, physical management,
organic manuring, row orientation, crop choice/growing salt tolerant crops,
appropriate/well adjusted fertilization

• Developing salt tolerant crops

• Policy formulation

8.6.2 Description of Salinity Management Options

8.6.2.1 Removing Surface Salts/Scraping

The total salts and sodium must be reduced before plants can grow normally. The
only effective way to reduce salts in soil is to remove them. If the salts are accumu-
lated at the surface and forms a thick layer, the simple and easiest way to remove
them is to scrape them out (i.e., take off the layer). Soils having a shallow water
table, or a highly impermeable profile; surface flushing of salts from soils that
contain salt crusts at the surface may be practiced to ameliorate the saline soil.

8.6.2.2 Control of Saline Water

There are two areas of concern of saline soils; recharge and discharge areas. We
should realize that salinity is a water problem in most cases. Excess water at
the recharge area causes most salinity problems. Preventing the accumulation and
resulting deep percolation of water to the bedrock is important. Excess water in
recharge areas may arise as a result of man-made ponding, excess accumulation
of snow, excessive summer fallowing, excess annual cropping, and decreased for-
age and perennial cropping. Control of water accumulation in recharge areas can be
established by drainage. Care should be taken when attempting any type of drainage
as it may result in causing salinity elsewhere.
There are also different management strategies for saline discharge sites. The
goal of discharge management should not be to remove salts completely, rather
decrease the salt concentration in the top 30 cm of the soil. Practicing direct seeding
in these areas reduces evaporation and increases deep percolation of water. This