SWAT - soil.layer.nutrients.nitrogen¶

mef_agri.models.soil.layer.nutrients.nitrogen.model_swat.py

Nitrate and Ammonia¶

class mef_agri.models.soil.layer.nutrients.nitrogen.model_swat.N_NO3_NH4_V2009(**kwargs)¶

Soil layer model for mineral nitrogen which contains the \(NO_3^-\) and the \(NH_4^+\)-pool. Nitrification is the only process considered herein - no losses such as nitrate leaching, denitrification or ammonia volatilization.

kwargs \(\rightarrow\) mef_agri.models.base.Model

NH4()¶

MQ - State

\(s_{\textrm{NH}_{4}^+,i,k}\ [\frac{kg}{ha}]\)

Returns:: amount of ammonium in the soil layer
Return type:: numpy.ndarray

NH4_uptake()¶

MQ - Random Output

\(s_{\textrm{NH}_{4}^{+}-u,i,k}\ [\frac{kg}{ha}]\)

Returns:: amount of ammonium removed from soil layer by the crop
Return type:: numpy.ndarray

NO3()¶

MQ - State

\(s_{\textrm{NO}_{3}^-,i,k}\ [\frac{kg}{ha}]\)

Returns:: amount of nitrate in the soil layer
Return type:: numpy.ndarray

NO3_uptake()¶

MQ - Random Output

\(s_{\textrm{NO}_{3}^{-}-u,i,k}\ [\frac{kg}{ha}]\)

Returns:: amount of nitrate removed from soil layer by the crop
Return type:: numpy.ndarray

fc()¶

RQ - from model with id 'zone.soil'

\(s_{\textrm{W-fc},0}\ [\ ]\)

Returns:: soil moisture at field capacity
Return type:: Requirement

initialize(epoch)¶

Only the super-call is done here.

Parameters:: epoch (datetime.date) – initialization epoch

lt()¶

RQ - from model with id '.__parent__.__parent__' (parent soil layer)

\(s_{\textrm{lt},i,0}\ [mm]\)

Returns:: layer thickness
Return type:: Requirement

ltemp()¶

RQ - from model with id '.__parent__.__parent__.temperature' (temperature model of parent soil layer)

\(s_{\textrm{T-t},i,k}\ [^\circ C]\)

Returns:: soil layer temperature
Return type:: Requirement

lwa()¶

RQ - from model with id '.__parent__.__parent__.water' (water model of parent soil layer)

\(s_{\textrm{W-a},i,k}\ [mm]\)

Returns:: water amount of soil layer
Return type:: Requirement

nitrification()¶

MQ - Random Output

\(s_{\textrm{N-nit},i,k}\ [\frac{kg}{ha}]\)

Returns:: amount of ammonium which is removed from the pool at current day (i.e. added to the NO3-pool)
Return type:: numpy.ndarray

update(epoch)¶

The following computations are performed

nitrification temperature factor - [R1] (equ. 3:1.3.1)
nitrification soil water factor - [R1] (equ. 3:1.3.2, 3:1.3.3)
nitrification factor - [R1] (equ. 3:1.3.6)
nitrification rate - [R1] (equ. 3:1.3.11 with setting volatilization factor to zero \(\Rightarrow\) equ. 3:1.3.11 is equal to equ. 3:1.3.8)
update N-pools

Parameters:: epoch (datetime.date) – current evaluation epoch

wp()¶

RQ - from model with id 'zone.soil'

\(s_{\textrm{W-wp},0}\ [\ ]\)

Returns:: soil moisture at wilting point
Return type:: Requirement

Nitrate, Ammonia and organic N¶

class mef_agri.models.soil.layer.nutrients.nitrogen.model_swat.N_NO3_NH4_Norg_V2009(**kwargs)¶

Contrary to N_NO3_NH4_V2009, this model additionally considers the organic N-pool and mineralization. Again no losses such as nitrate leaching, denitrification or ammonia volatilization.

Inherits from N_NO3_NH4_V2009

kwargs \(\rightarrow\) mef_agri.models.base.Model

N_org()¶

MQ - State

\(s_{\textrm{N-org},i,k}\ [\frac{kg}{ha}]\) - [R1] (section 3:5.1)

Returns:: organic N-pool
Return type:: numpy.ndarray

N_org_add()¶

MQ - Random Output

\(s_{\textrm{N-}\Delta\textrm{o},i,k}\ [\frac{kg}{ha\cdot day}]\) - [R1] (equ. 3:5.1.2b)

Returns:: input from decomposed crop residuals to the organic N-pool
Return type:: numpy.ndarray

chum_res()¶

RQ - from model with id '.__parent__.carbon' (carbon model from parent nutrient model)

\(s_{\textrm{C-rdh},i,k}\ [\frac{kg}{ha\cdot day}]\)

Returns:: amount of decomposed C from crop residuals which is added to the organic C-pool (humus)
Return type:: Requirement

cnorg()¶

RQ - from model with id '.__parent__' (parent nutrient model)

\(s_{\textrm{CN-o},i,k}\ [\ ]\)

Returns:: C/N ratio of organic matter in the soil layer
Return type:: Requirement

fmin()¶

RQ - from model with id '.__parent__.carbon' (carbon model from parent nutrient model)

\(s_{\textrm{min},i,k}\ [\frac{1}{day}]\)

Returns:: mineralization rate
Return type:: Requirement

initialize(epoch)¶

N_org_add() is initialized with a zero array.

Parameters:: epoch (datetime.date) – initialization epoch

mineralized_N()¶

MQ - Random Output

\(s_{\textrm{N-mo},i,k}\ [\frac{kg}{ha\cdot day}]\)

Returns:: mineralized N from organic N-pool
Return type:: numpy.ndarray

update(epoch)¶

Additionally to N_NO3_NH4_V2009.update(), the following computations are performed

increase of organic N-pool (proportional to humified C) - [R1] (equ. 3:5.1.2b)
mineralization of organic N which feeds the \(\textrm{NH}_4^+\)-pool - [R1] (equ. 3:5.1.2b)

Parameters:: epoch (datetime.date) – current evaluation epoch