Soil Science

The exchangeable sodium ratio (ESR) can be calculated as

A) $${\text{ESR}} = \frac{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}$$ B) $${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{\sqrt {{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)} }}$$ C) $${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {{\text{K}}^ + }} \right)}}$$ D) $${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}$$

Answer & Solution

Correct Answer: Option D

The exchangeable sodium percentage measures the production of cation exchange sites occupied by sodium.
The exchangeable sodium ratio (ESR) is the relative amount of the sodium ion present on the soil surface, expressed as a percentage of the total cation exchange capacity.
It is calculated as:

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}$$

The exchangeable sodium ratio (ESR) can be calculated as

The exchangeable sodium ratio (ESR) can be calculated as

Join the Discussion

Related Questions on Soil Science