Correct Answer - Option 2 : Medium Sodium Water
Concept:
Sodium-ion in small amounts is good for plants. But excess sodium ion creates the problem for both plant and soil. Excess sodium contributes to salinity and it is toxic for some sensitive crops.
Soil with high sodium content becomes very plastic in nature in the wet stage, which shows low permeability and poor aeration.
This excessiveness of sodium ion is measured in terms of sodium absorption ratio (SAR).
\({\rm{SAR}} = \frac{{\left[ {{\rm{N}}{{\rm{a}}^ + }} \right]}}{{\sqrt {\frac{{\left[ {{\rm{C}}{{\rm{a}}^{2 + }}} \right] + \left[ {{\rm{M}}{{\rm{g}}^{2 + }}} \right]}}{2}} }}\)
Where,
[Na+] = concentration of sodium ion in milli-equivalent per liter
[Ca2+] = concentration of calcium ion in milli-equivalent per liter
[Mg2+] = concentration of magnesium ion in milli-equivalent per liter
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SAR
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Type of water
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0-10
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Low sodium
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10-18
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Medium sodium
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18-26
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High sodium
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>26
|
Very high sodium
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