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N from previous years' organic fertilization (term F in DPI balance)

Source: R/calc_N_from_previous_organic.R
organic_previous_years_N.Rd

Residual N available to the crop from organic fertilizer applied in previous years. DPI formula: F = N_applied_previous_year (kg/ha) x Recovery_coeff. Recovery coefficient depends on organic type and application frequency (Guida DPI 2026, sec. 3.1.6).

Usage

organic_previous_years_N(N_applied_previous_year, source, frequency)

Arguments

N_applied_previous_year

Numeric. Total N (kg/ha) applied in the previous year from organic fertilization (same type and frequency as current practice).

source

Character. Organic fertilizer source (e.g. "Cattle slurry", "Composted manure").

frequency

Character. Application frequency: "every year", "every two years", "every three years", or "occasional".

Value

Numeric. F in kg/ha (residual N from previous years' organic). Returns 0 if N_applied_previous_year is 0, NA, or NULL.

References

DPI Emilia-Romagna, Guida alla fertilizzazione 2026, sec. 3.1.6 - N da fertilizzazioni organiche degli anni precedenti.

Examples

organic_previous_years_N(100, "Cattle slurry", "every year")   # 30 kg/ha
#> [1] 30
organic_previous_years_N(80, "Composted manure", "every two years")  # 24 kg/ha
#> [1] 24