# Model Documentation

### | Version 4.0

created with goxygen 0.21.1

# 51_nitrogen

# Nitrogen (51_nitrogen)

## Description

The nitrogen module calculates nitrogeneous emissions before technical mitigation, including N2O, NOx, NH3, NO3- and N2.

## Interfaces

Interfaces to other modules

### Input

module inputs (A: ipcc2006_sep16 | B: off)
| Description | Unit | A | B
--- | --- | --- | --- | ---
vm_btm_reg (i, emis_source, pollutants) | Regional emissions before technical mitigation | \(Tg/yr\) | x | x
vm_emissions_reg (i, emis_source, pollutants) | Regional emissions by source and gas after technical mitigation N CH4 C | \(Tg/yr\) | x |
vm_manure_confinement (i, kli, awms_conf, npk) | Manure excreted in confinements managed in different awms | \(10^6 t X\) | x |
vm_manure (i, kli, awms, npk) | Calculation of manure excreted in confinements | \(10^6 t X\) | x |
vm_manure_recycling (i, npk) | Manure being recycled to croplands | \(10^6 t X\) | x |
vm_nr_inorg_fert_reg (i, land_ag) | inorganic fertilizer application | \(Tg N/yr\) | x |
vm_nr_som (j) | Release of soil organic matter | \(Tg N/yr\) | x |
vm_res_recycling (i, npk) | Residues recycled to croplands in respective nutrients Nr P K units | \(10^6 tX\) | x |

### Output

## Realizations

### (A) ipcc2006_sep16

The nitrogen module calculates nitrogeneous emissions before technical mitigation, including N2O, NOx, NH3, NO3- and N2. The model receives information on nitrogen flows from 50_nr_soil_budget, 55_awms, 18_residues, 59_som, and it provides the emissions to the module 56_ghg_policy. Emissions factors estimates are largely based on the IPCC 2006 Guidelines for National Greenhouse Gas Inventories (IPCC (2006).), as described in (Bodirsky et al. (2012).).

Nitrogeneous emissions stem from manure applied to croplands, inorganic fertilizers, crop residues decaying on fields, soil organic matter loss, animal waste management, and manure excreted on pasture land. Additionally, part of the NH3 and NOx emissions as well as leached NO3 later result in indirect emissions of N2O when they are redeposited, nitrified and dinitrified.

Manure applied to croplands:

\[\begin{multline*} vm\_btm\_reg(i2,"man\_crop",n\_pollutants\_direct) = vm\_manure\_recycling(i2,"nr") \cdot f51\_ef\_n\_soil(n\_pollutants\_direct,"man\_crop") \end{multline*}\]

inorganic fertilizers:

\[\begin{multline*} vm\_btm\_reg(i2,"inorg\_fert",n\_pollutants\_direct) = \sum_{land\_ag}vm\_nr\_inorg\_fert\_reg(i2,land\_ag) \cdot f51\_ef\_n\_soil(n\_pollutants\_direct,"inorg\_fert") \end{multline*}\]

crop residues decaying on fields:

\[\begin{multline*} vm\_btm\_reg(i2,"resid",n\_pollutants\_direct) = vm\_res\_recycling(i2,"nr") \cdot f51\_ef\_n\_soil(n\_pollutants\_direct,"resid") \end{multline*}\]

soil organic matter loss:

\[\begin{multline*} vm\_btm\_reg(i2,"som",n\_pollutants\_direct) = \sum_{cell(i2,j2)}vm\_nr\_som(j2) \cdot f51\_ef\_n\_soil(n\_pollutants\_direct,"som") \end{multline*}\]

animal waste management:

\[\begin{multline*} vm\_btm\_reg(i2,"awms",n\_pollutants\_direct) = \sum_{kli,awms\_conf}\left( vm\_manure\_confinement(i2,kli,awms\_conf,"nr") \cdot f51\_ef3\_confinement(i2,kli,awms\_conf,n\_pollutants\_direct)\right) \end{multline*}\]

and manure excreted on pasture land:

\[\begin{multline*} vm\_btm\_reg(i2,"man\_past",n\_pollutants\_direct) = \sum_{awms\_prp,kli}\left( vm\_manure\left(i2, kli, awms\_prp, "nr"\right) \cdot f51\_ef3\_prp(i2,n\_pollutants\_direct,kli)\right) \end{multline*}\]

Indirect emissions from NH3, NOx and NO3:

\[\begin{multline*} vm\_btm\_reg(i2,emis\_source\_n51,"n2o\_n\_indirect") = \sum_{pollutant\_nh3no2\_51}vm\_emissions\_reg(i2,emis\_source\_n51,pollutant\_nh3no2\_51) \cdot f51\_ipcc\_ef("ef\_4","best") + vm\_emissions\_reg(i2,emis\_source\_n51,"no3\_n") \cdot f51\_ipcc\_ef("ef\_5","best") \end{multline*}\]

> Limitations There are no known limitations.

### (B) off

Emissions are set to zero.

> Limitations There are no known limitations.

## Definitions

### Objects

module-internal objects (A: ipcc2006_sep16 | B: off)
| Description | Unit | A | B
--- | --- | --- | --- | ---
f51_ef3_confinement (i, kli, awms_conf, n_pollutants_direct) | emissions from manure managed in confinement for various emission types X | \(tX-N/tN\) | x |
f51_ef3_prp (i, n_pollutants_direct, kli) | emissions from manure on pasture range and paddocks for various emission types X | \(tX-N/tN\) | x |
f51_ef_n_soil (n_pollutants_direct, emis_source_n_cropsoils51) | ipcc emission factors for various emission types X | \(tX-N/tN\) | x |
f51_ipcc_ef (ipcc_ef51, emis_uncertainty51) | ipcc emission factors for various emission types X | \(tX-N/tN\) | x |
q51_emissionbal_awms (i, n_pollutants_direct) | estimates various emission types X from animal waste management systems before technical mitigation | \(Mt X-N\) | x |
q51_emissionbal_man_past (i, n_pollutants_direct) | estimates various emission types X from manure on pasture land before technical mitigation | \(Mt X-N\) | x |
q51_emissions_indirect_n2o (i, emis_source_n51) | estimates various emission types X from volatilisation and leaching | \(Mt X-N\) | x |
q51_emissions_inorg_fert (i, n_pollutants_direct) | estimates various emission types X from inorganic fertilizer before technical mitigation | \(Mt X-N\) | x |
q51_emissions_man_crop (i, n_pollutants_direct) | estimates various emission types X from manure on cropland before technical mitigation | \(Mt X-N\) | x |
q51_emissions_resid (i, n_pollutants_direct) | estimates various emission types X from residues before technical mitigation | \(Mt X-N\) | x |
q51_emissions_som (i, n_pollutants_direct) | estimates various emission types X from soil organic matter loss before technical mitigation | \(Mt X-N\) | x |

### Sets

sets in use
| description
--- | ---
awms | animal waste management systems
awms_conf | animal waste management systems in confinements
emis_source | Emission sources
emis_source_n51(emis_source) | Emission sources from agriculture
emis_source_n_cropsoils51(emis_source) | activities that lead to emissions
emis_uncertainty51 | Different estimates for emission parameters
i | World regions
ipcc_ef51 | ipcc Emission factors
kli(kap) | Livestock products
land_ag(land) | Agricultural land pools
npk(nutrients) | Plant nutrients
n_pollutants_direct(n_pollutants) | subset of n pollutants
pollutants(pollutants_all) | subset of pollutants_all that can be taxed

## Authors

Benjamin Leon Bodirsky

## See Also

18_residues, 50_nr_soil_budget, 55_awms, 56_ghg_policy, 59_som

## References

Bodirsky, Benjamin Leon, Alexander Popp, Isabelle Weindl, Jan Philipp Dietrich, Susanne Rolinski, Lena Scheiffele, Christoph Schmitz, and Hermann Lotze-Campen. 2012. “Current State and Future Scenarios of the Global Agricultural Nitrogen Cycle.” Biogeosciences Discuss. 9 (3): 2755–2821. doi:10.5194/bgd-9-2755-2012.

IPCC. 2006. “2006 IPCC Guidelines for National Greenhouse Gas Inventories, Prepared by the National Greenhouse Gas Inventories Programme.”