Classifies soil phosphorus availability using the Olsen method, following
DPI Emilia-Romagna 2026 (Fert_Office v1.26 foglio Gri_P). The input may be
expressed either as elemental P or as P2O5 equivalent; the conversion
factor is P2O5 = P / 0.436681.
Usage
classify_P_olsen(
value,
unit = c("P", "P2O5"),
p_availability.table = NFert::p_availability.table,
p_availability_meta = NFert::p_availability_meta
)Arguments
- value
Numeric. Olsen phosphorus value in ppm.
- unit
Either
"P"or"P2O5"(default"P").- p_availability.table
Lookup table, default
NFert::p_availability.table.- p_availability_meta
Conversion metadata, default
NFert::p_availability_meta.
Value
A list with:
value_ppm_P,value_ppm_P2O5: input converted to both units.ID_Gri_P: class id (1 molto bassa ... 5 molto elevata).rating: human-readable class.soil_class: DPI "Classe dotaz." (molto scarso,scarso,normale,molto alto).strategy: one of"Arricchimento","Mantenimento","Riduzione".
Examples
classify_P_olsen(value = 15, unit = "P2O5")
#> $value_ppm_P
#> [1] 6.550215
#>
#> $value_ppm_P2O5
#> [1] 15
#>
#> $ID_Gri_P
#> [1] 2
#>
#> $rating
#> [1] "low"
#>
#> $soil_class
#> [1] "scarso"
#>
#> $strategy
#> [1] "Arricchimento"
#>
classify_P_olsen(value = 6.55, unit = "P")
#> $value_ppm_P
#> [1] 6.55
#>
#> $value_ppm_P2O5
#> [1] 14.99951
#>
#> $ID_Gri_P
#> [1] 2
#>
#> $rating
#> [1] "low"
#>
#> $soil_class
#> [1] "scarso"
#>
#> $strategy
#> [1] "Arricchimento"
#>