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Horizonte B espodico (SiBCS Cap 2, p 62-65; v0.7)

Source: R/diagnostics-horizons-sibcs.R
B_espodico.Rd

Subsuperficial com acumulo iluvial de Al + Fe + materia organica; espessura \>= 2.5 cm. Tipos: Bs, Bhs, Bh, ortstein. Reuso de spodic (WRB) que ja codifica criterios essencialmente identicos.

Usage

B_espodico(pedon, ...)

Arguments

pedon

A PedonRecord.

...

Reserved for future arguments.

Value

A DiagnosticResult recording whether the diagnostic is present, the qualifying layers, and the supporting evidence.

Details

In the morphological mode the horizon is also read from its designation. Since v0.9.247 that includes the "ir" of the older surveys (Bir, B2ir, B22irx), the illuvial iron that the present notation writes "s": the mode read "h" and "s" only.

Since v0.9.255 a horizon that the WRB test does not find is looked for by item (a) of the book (p. 65), in both modes. The B espodico has an "acumulacao iluvial de compostos organometalicos" and, by that item, "um horizonte E (albico ou nao) sobrejacente e cores umidas de acordo com um dos itens a seguir: 1) matiz 5YR ou mais vermelho; 2) matiz 7,5YR com valor 5 ou menor e croma 4 ou menor; 3) matiz 10YR, com valor e croma 3 ou menor; 4) cores neutras com valor 3 ou menor". A B layer of 2.5 cm or more passes when:

  • an E lies above it in the profile;

  • its moist colour is one of the four;

  • its organic carbon is 0.5% or more and at least twice that of the nearest E above it; and

  • no cerosidade is recorded in it.

The last two stand for the illuvial accumulation, which the sheets do not measure where there is no oxalate extraction. The first takes the form the book gives in item (b)(3) for aluminium and iron by oxalate, "valor 0,50 ou maior, sendo este valor pelo menos o dobro do encontrado no horizonte sobrejacente"; the second keeps out the B whose illuvial material is clay. It is a reading by analogy, decided on 2026-10-13, and not the letter of the book: the colours alone are those of the B textural of many an Argissolo below an E. Items (b) and (c), the cementation and the ortstein, are not tested.