How to Prevent and Manage Soil Salinity

1. Choose a crop that fit your field's conditions4. Use appropriate fertilizers types The fertilizers
- Soil type - water infiltration capacity, how much airtype and their quantities should coincide with to the
does the soil contain, how much water will be neededrequirements of the crop and with nutrients which
to wash the soil in order to avoid salinity build up.are already in the soil. There are fertilizers which
Does your soil have special drainage problems? Forcontain salts which are not taken up by plants in large
example, it is better avoid planting a salt sensitiveamounts, such as chlorides. These salts tend to
crop in a soil which is not well drained.accumulate in the soil.
- The microclimate conditions in the field - parameters5. Have your soil tested periodically Soil analysis gives
such as wind direction and solar radiation may affectyou a better indication of the salt content in the soil,
water consumption of the crop.without which you'll be only guessing. Guessing often
- The agricultural history of the field - did saltscomes close enough, but in many cases growers
accumulate in the soil during a previous crop?realize there's a salinity problem only after yields are
- Irrigation water quality - Check the quality of thedecreased or crop quality is reduced.
available source water. What kind of salts does itA practical approach in order to prevent salinity
contain and what is the total level of salts in it?buildup early enough is sampling the soil 5 times over
- type of irrigation system and its distribution - whata growing period of 8 months (a test every 6 weeks
type of irrigation system are you going to use? is itor so). It is recommended to do at least one water
flood irrigation, sprinklers, pivot or drip irrigation? eachanalysis as well. The tests will indicate any change in
type of irrigation system has its own watersoil content, allowing you to adjust the fertilization
distribution pattern, depending also on the soiland irrigation regimen as needed. This is the
properties. make sure the emitters are set in thecheapest, most practical way to follow up on salinity
appropriate spacing, to allow uniform irrigationstatus, keeping your crop quality and yield at optimal
depending on your soil type.level.
2. Know the leaching requirement for your crop6. And if after all that, you still face a salinity
Irrigation water amounts must coincide the growingproblem... When you identify a salinity problem during
stage of your crop. Apply the minimum needed tothe growing season, it is recommended to flush the
flush salts from soil. This means that you alwaysfield, even if it means risking some crop damage,
have to give a little more water than the croprather than allowing further deterioration of the crop
consumption, to allow leaching of salts below the rootdue to salinity.
zone. Remember that heavier soils require largerFlushing applications should be carefully planned
water applications than lighter soils, in order to avoidaccording to the crop conditions and growth stage. In
salinity buildup.light soils, which drain easily, the impact of flushing on
The leaching requirement is expressed as:the crop is usually insignificant. In heavy soils, water
LR = Water leached/Water appliedinfiltration and drainage problems may be
A general equation to calculate the leachingencountered, resulting in excess of water and lack of
requirement isair to the roots. Flushing heavy soils is a prolonged
LR (%) =ECiw/(5ECth-ECiw)process and its final result is difficult to anticipate in
Where ECiw is the EC of the irrigation water, andadvance.
ECth is the threshold salinity measured in theTherefore, extra care should be taken when growing
saturated soil extract, above which yield begins doon heavy soils, as to not reach salinity buildup at all,
decline (both in ds/m).or at least identify the problem early enough, when
The total amount of water to be applied is AW = ETsalts levels are still relatively easy to flush. If all else
(1-LR)fails and flushing is the chosen course of action, in
Where AW is the amount of water to be applied andheavier soils, not more than the maximal water
ET is the water consumption based onamount that can be absorbed by the soil should be
evapotranspiration.applied, and the longest intervals possible should be
3. Keep the right Intervals between irrigationsmaintained. In the meantime, fertilization should be
Irrigation regimen and intervals must be appropriatebased only on Nitrogen and only the minimum amount
to the soil conditions and to growth stage of theshould be applied.
crop. Frequent and shallow (superficial) applicationsThe water used for flushing should be the highest
result in salt accumulation in the root zone, whilequality possible, because the purpose of the flushing
larger applications, in longer intervals, will flush theprocess is to decrease the soil salinity to the levels of
salts below the root zone.the irrigation water.