Estimates direct and indirect N2O emissions from soils due to fertilisation, excreta deposition and crop residues, following a Tier 1-style IPCC approach.
Usage
calc_emissions_soil(
n_fertilizer_synthetic = 0,
n_fertilizer_organic = 0,
n_excreta_pasture = 0,
n_crop_residues = 0,
area_ha = NULL,
soil_type = "well_drained",
climate = "temperate",
ef_direct = NULL,
include_indirect = TRUE,
gwp_n2o = 273,
boundaries = NULL
)Arguments
- n_fertilizer_synthetic
Numeric. Synthetic N fertiliser applied (kg N/year). Default = 0.
- n_fertilizer_organic
Numeric. Organic N fertiliser applied (kg N/year). Default = 0.
- n_excreta_pasture
Numeric. N excreted directly on pasture (kg N/year). Default = 0.
- n_crop_residues
Numeric. N in crop residues returned to soil (kg N/year). Default = 0.
- area_ha
Numeric. Total farm area (ha). Optional, for per-hectare metrics.
- soil_type
Character. "well_drained" or "poorly_drained". Default = "well_drained".
- climate
Character. "temperate" or "tropical". Default = "temperate".
- ef_direct
Numeric. Direct EF for N2O-N (kg N2O-N per kg N input). If NULL, uses IPCC-style values by soil/climate.
- include_indirect
Logical. Include indirect N2O (volatilisation + leaching)? Default = TRUE.
- gwp_n2o
Numeric. GWP of N2O. Default = 273 (IPCC AR6).
- boundaries
Optional. Object from
set_system_boundaries(). If soil is excluded, returnsco2eq_kg = 0.
Value
A list with at least source="soil" and co2eq_kg (numeric),
plus detailed breakdown metadata when included by boundaries.
Details
IMPORTANT: When system boundaries exclude soil, this function must return
a list with source = "soil" and co2eq_kg = 0 (numeric zero) to match
partial-boundaries integration tests.
Examples
# \donttest{
# Direct + indirect (default), temperate, well-drained
calc_emissions_soil(
n_fertilizer_synthetic = 2500,
n_fertilizer_organic = 500,
n_excreta_pasture = 1200,
n_crop_residues = 300,
area_ha = 150
)
#> $source
#> [1] "soil"
#>
#> $soil_conditions
#> $soil_conditions$soil_type
#> [1] "well_drained"
#>
#> $soil_conditions$climate
#> [1] "temperate"
#>
#>
#> $nitrogen_inputs
#> $nitrogen_inputs$synthetic_fertilizer_kg_n
#> [1] 2500
#>
#> $nitrogen_inputs$organic_fertilizer_kg_n
#> [1] 500
#>
#> $nitrogen_inputs$excreta_pasture_kg_n
#> [1] 1200
#>
#> $nitrogen_inputs$crop_residues_kg_n
#> [1] 300
#>
#> $nitrogen_inputs$total_kg_n
#> [1] 4500
#>
#>
#> $emissions_breakdown
#> $emissions_breakdown$direct_n2o_kg
#> [1] 70.714
#>
#> $emissions_breakdown$indirect_volatilization_n2o_kg
#> [1] 9.271
#>
#> $emissions_breakdown$indirect_leaching_n2o_kg
#> [1] 15.911
#>
#> $emissions_breakdown$total_indirect_n2o_kg
#> [1] 25.182
#>
#> $emissions_breakdown$total_n2o_kg
#> [1] 95.896
#>
#>
#> $co2eq_kg
#> [1] 26179.72
#>
#> $emission_factors
#> $emission_factors$ef_direct
#> [1] 0.01
#>
#> $emission_factors$ef_volatilization
#> [1] 0.01
#>
#> $emission_factors$ef_leaching
#> [1] 0.0075
#>
#> $emission_factors$gwp_n2o
#> [1] 273
#>
#> $emission_factors$factors_source
#> [1] "IPCC-style defaults (temperate, well_drained)"
#>
#>
#> $methodology
#> [1] "Tier 1-style (direct + indirect)"
#>
#> $standards
#> [1] "IPCC 2019 Refinement, IDF 2022"
#>
#> $date
#> [1] "2025-09-11"
#>
#> $per_hectare_metrics
#> $per_hectare_metrics$n_input_kg_per_ha
#> [1] 30
#>
#> $per_hectare_metrics$n2o_kg_per_ha
#> [1] 0.639
#>
#> $per_hectare_metrics$co2eq_kg_per_ha
#> [1] 174.53
#>
#> $per_hectare_metrics$emission_intensity_kg_co2eq_per_kg_n
#> [1] 5.82
#>
#>
#> $source_contributions
#> $source_contributions$synthetic_fertilizer_pct
#> [1] 55.6
#>
#> $source_contributions$organic_fertilizer_pct
#> [1] 11.1
#>
#> $source_contributions$excreta_pasture_pct
#> [1] 26.7
#>
#> $source_contributions$crop_residues_pct
#> [1] 6.7
#>
#> $source_contributions$direct_emissions_pct
#> [1] 73.7
#>
#> $source_contributions$indirect_emissions_pct
#> [1] 26.3
#>
#>
# Direct-only
calc_emissions_soil(n_fertilizer_synthetic = 2000, include_indirect = FALSE)
#> $source
#> [1] "soil"
#>
#> $soil_conditions
#> $soil_conditions$soil_type
#> [1] "well_drained"
#>
#> $soil_conditions$climate
#> [1] "temperate"
#>
#>
#> $nitrogen_inputs
#> $nitrogen_inputs$synthetic_fertilizer_kg_n
#> [1] 2000
#>
#> $nitrogen_inputs$organic_fertilizer_kg_n
#> [1] 0
#>
#> $nitrogen_inputs$excreta_pasture_kg_n
#> [1] 0
#>
#> $nitrogen_inputs$crop_residues_kg_n
#> [1] 0
#>
#> $nitrogen_inputs$total_kg_n
#> [1] 2000
#>
#>
#> $emissions_breakdown
#> $emissions_breakdown$direct_n2o_kg
#> [1] 31.429
#>
#> $emissions_breakdown$indirect_volatilization_n2o_kg
#> [1] 0
#>
#> $emissions_breakdown$indirect_leaching_n2o_kg
#> [1] 0
#>
#> $emissions_breakdown$total_indirect_n2o_kg
#> [1] 0
#>
#> $emissions_breakdown$total_n2o_kg
#> [1] 31.429
#>
#>
#> $co2eq_kg
#> [1] 8580
#>
#> $emission_factors
#> $emission_factors$ef_direct
#> [1] 0.01
#>
#> $emission_factors$ef_volatilization
#> [1] NA
#>
#> $emission_factors$ef_leaching
#> [1] NA
#>
#> $emission_factors$gwp_n2o
#> [1] 273
#>
#> $emission_factors$factors_source
#> [1] "IPCC-style defaults (temperate, well_drained)"
#>
#>
#> $methodology
#> [1] "Tier 1-style (direct only)"
#>
#> $standards
#> [1] "IPCC 2019 Refinement, IDF 2022"
#>
#> $date
#> [1] "2025-09-11"
#>
#> $source_contributions
#> $source_contributions$synthetic_fertilizer_pct
#> [1] 100
#>
#> $source_contributions$organic_fertilizer_pct
#> [1] 0
#>
#> $source_contributions$excreta_pasture_pct
#> [1] 0
#>
#> $source_contributions$crop_residues_pct
#> [1] 0
#>
#> $source_contributions$direct_emissions_pct
#> [1] 100
#>
#> $source_contributions$indirect_emissions_pct
#> [1] 0
#>
#>
# Boundary exclusion example
b <- list(include = c("energy", "manure")) # soil not included
calc_emissions_soil(n_fertilizer_synthetic = 1000, boundaries = b)$co2eq_kg # 0
#> [1] 0
# }