New class: cation area density in soil

[celineaubert]

cation area density in soil

• subclassOf area density http://purl.obolibrary.org/obo/PATO_0001351
• subclassOf inheres in soil
• has_exact_synonym: cation exchange capacity, CEC
• definition Cation exchange capacity is a measure of the total negative charges within the soil that adsorb plant nutrient cations. In this case, cations refers to the the basic cations, calcium (Ca+2), magnesium (Mg+2), potassium (K+1) and sodium (Na+1) and the acidic cations, hydrogen (H+1) and aluminum (Al+3). http://extension.uga.edu/publications/detail.cfm?number=C1040 http://www.clemson.edu/public/regulatory/ag_svc_lab/soil_testing/cec.html

[KrishnaTO]

@celineaubert Should the class be expanded or limited?

Expanded: Cation is a valid ChEBI (http://purl.obolibrary.org/obo/CHEBI_36916) class, which would require adoption of all 'chemical-orientated' associations, not limited to

basic cations, calcium (Ca+2), magnesium (Mg+2), potassium (K+1) and sodium (Na+1) and the acidic cations, hydrogen (H+1) and aluminum (Al+3)

Based on sources, this may be intended.

Limited: Revise class to basic cation area density in soil, which would require some additional classes:

• basic cation [CheBi]
  • 'basic cation' area density [AgrO]
    • 'basic cation area density' in soil [ENVO]

[celineaubert]

@KrishnaTO , I don't know. The term used by the community is : cation exchange capacity To simplify, we can also no link the term to Chebi at all.

[KrishnaTO]

@celineaubert CEC seemed the root intent, rather than 'cation' 'area density' 'in soil', which I added as a related_synonym instead. The definition below was included as testing methods do not specifically target any ions. Current relations to cation and data item. Please review in commit and let me know if it's acceptable?
""" A data item which quantitatively measures the exchangable cations, where exchangable cations can include, but not limited to, calcium (Ca++), magnesium (Mg++), potassium (K+), ammonium (NH4+), hydrogen (H+) and sodium (Na+). """

Ideally, a new issue for units (meq/g, millequivalents per grams) should be created. Specific class for measuring CEC 'in soil' is additionally added as a subclass.

[pbuttigieg]

If CEC was the main intent, then this has been resolved in earlier PRs