The humus form of the Referentiel pedologique 2008

Attaches the epipedon ("episolum humifere") of a pedon to a humus form of Annex 1 of the French Referentiel pedologique 2008 (pp. 327-355): the four functional types (mull, moder, mor, amphimus) and their forms. The horizons are read as classify_rp2008 reads them (the RP notation where written, else the data), then, in order: H horizons at the top leave the form to the histosols (p. 351); an OHta makes a tangel, an An an anmoor; O horizons directly over an X, R or D give the forms without fine mineral earth (pp. 348-349); site$land_use or a ploughed L gives the open-land forms (p. 337); otherwise the key of Figure 2 (p. 354) is walked on the O and A horizons, and its outcome is made hydromorphic when the first mineral layer is a G or bears g (p. 350).

Usage

humus_form_rp(pedon)

Arguments

pedon: A PedonRecord.

Value

A list: form (the code of the form, NA when undecided), name (its name as printed), type (mull, moder, mor or amphimus, NA when undecided or for the anmoor), label (the name of the form when decided, else of the type when decided, else NA: what follows "a" in the name of the solum), group (aerated, hydromorphic, no_fine_earth, open_land, histic or NA), decided, route ("horizons", "recorded" or "none"), candidates (the codes of the forms still possible), no_form_possible (TRUE when the horizons may also fit no form), recorded (the recorded site$humus_form), conflict (the recorded form disagrees with the horizons), qualifiers (a data frame: qualifier, group, value, degree (pass, imperfect, undecided), page, note), path and answers (the walk of the key), missing (the attributes that would decide it) and notes.

Details

The key reads the kind of the O horizons (OL, OLn, OLv, OF, OH: the notation, or fine_organic_matter_pct), their zoogenic character (the suffixes zo and noz, or o_zoogenic), their lateral cover (lateral_cover_pct, or the parentheses of the RP notation), the thickness of the OH and the biological structure of the A (biogenic_aggregates_pct, else the structure). Every test is three-valued: what is not recorded leaves the form undecided among its candidates. A recorded site$humus_form decides when the horizons leave the form undecided (even outside the forms they leave possible, the conflict reported); when the horizons decide another form, they prevail and the conflict is reported.

References

Baize D., Girard M.-C. (coord.) (2009). Referentiel pedologique 2008. AFES, Editions Quae, Versailles. Annex 1, pp. 327-355.

Examples

humus_form_rp(make_rp2008_example("organosols_holorganiques"))$label
#> [1] "tangel"