Re: Use of "n" suffix

The ‘n’ suffix symbol is used to indicate an “accumulation of exchangeable sodium” in the soil (12th KST, 2014). Its use is certainly indicated when levels of exchangeable sodium are diagnostic for natric horizons or Sodic and Natric subgroups. The ‘n’ suffix symbol can be used when levels of exchangeable sodium are below diagnostic levels in Soil Taxonomy if the effects sodium are observed or indicated. Dispersion of colloids, weakened/coarse soil structure, crusting, and a preponderance of sodium tolerant native plant species may indicate higher levels of sodium even when below diagnostic levels. The horizon suffix symbols are tools for the describer to indicate pedogenic processes or features observed even when the feature occurs below diagnostic levels for soil classification.