add "limed soil" and "manured soil" to the "enriched soil" hierarchy

[sierra-moxon]

ENVO:00003082 - enriched soil is currently defined as "A portion of enriched soil is a portion of soil with elevated levels of some material entity"

ENVO:00005766 - limed soil is currently defined as "Soil which has been amended with mineral additives to increase its pH", but is not currently defined as a subclass of enriched soil

ENVO:00005767 - manured soil is currently defined as "Soil which has, as a part, a portion of either fresh or processed animal manure", also not a subclass of enriched soil.

We may want to consider if we mean "enriched" as "improve or enhance the quality or value of" or "elevated levels of."? If the latter, then I think both should be added to the subclass hierarchy of "enriched soil."

This is a request from the NMDC team working on creating subsets (not currently official ENVO subsets) of ENVO terms.

[sierra-moxon]

We may also want to consider: ENVO:03600036 (pathogen suppressive soil) as enriched soil? From the definition of "pathogen suppressive soil" it is unclear to me if we mean that the soil is naturally occurring or enriched in some way to convey pathogen suppression (nor if it matters, really, but without clarification I am not sure if this should be a child of "enriched soil" or not).