EPIC - crop.stress¶

class mef_agri.models.crop.stress.model_epic.Stress(**kwargs)¶

Stress model which considers water-, temperature-, aeration and nitrogen-stress according to [R2] .

aeration_stress()¶

MQ - Random Output

\(c_{\textrm{astr},k}\ [\ ]\) - [R2] (equ. 49, 50)

Returns:: aeration stress factor
Return type:: numpy.ndarray

caf()¶

RQ - 'critical_aeration_factor' from model with id 'crop'

\(c_{\textrm{caf},0}\ [\ ]\)

Returns:: critical aeration factor of crop
Return type:: Requirement

growth_constraint()¶

MQ - Random Output

\(c_{\textrm{gc},k}\ [\ ]\) - [R2] (last paragraph in “Growth Constraints” > “Biomass”)

Returns:: (biomass) growth constraint (min. value of several stress factors)
Return type:: numpy.ndarray

initialize(epoch)¶

Initialization of stress factors with one vectors (i.e. no stress)

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

m1m()¶

RQ - moisture_1m from model with id 'zone.soil.supply'

\(s_{\textrm{W-m1m},k}\ [\ ]\)

Returns:: moisture of first meter of soil
Return type:: Requirement

nao()¶

RQ - 'n_amount_opt' from model with id 'crop.demand'

\(c_{\textrm{N-ao},k}\ [\frac{kg}{ha}]\)

Returns:: optimal N-amount in crop biomass
Return type:: Requirement

nitrogen_stress()¶

MQ - Random Output

\(c_{\textrm{N-str},k}\ [\ ]\) - [R2] (equ. 47)

Returns:: nitrogen stress factor
Return type:: numpy.ndarray

nsum()¶

RQ - 'nitrogen_sum' from model with id 'crop.uptake'

\(c_{\textrm{N-ups},k}\ [\frac{kg}{ha}]\)

Returns:: sum of nitrogen uptake of current crop/vegetation period
Return type:: Requirement

por()¶

RQ - 'porosity' from model with id 'zone.soil'

\(s_{\textrm{por},0}\ [\ ]\)

Returns:: soil porosity (fraction of total volume)
Return type:: Requirement

stemp()¶

RQ - 'temperature' from model with id 'zone.soil.surface.temperature'

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

Returns:: soil surface temperature
Return type:: Requirement

tb()¶

RQ - temperature_base from model with id 'crop.development'

\(c_{\textrm{D-tb},0}\ [^\circ C]\)

Returns:: crop specific base temperature
Return type:: Requirement

temperature_stress()¶

MQ - Random Output

\(c_{\textrm{tstr},k}\ [\ ]\) - [R2] (equ. 46)

Returns:: temperature stress factor
Return type:: numpy.ndarray

to()¶

RQ - temperature_opt from model with id 'crop.development'

\(c_{\textrm{D-to},0}\ [^\circ C]\)

Returns:: crop specific optimum temperature
Return type:: Requirement

update(epoch)¶

The following computations are performed

water_stress()
aeration_stress()
temperature_stress()
nitrogen_stress()
growth_constraint()

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

water_stress()¶

MQ - Random Output

\(c_{\textrm{W-str},k}\ [\ ]\) - [R2] (equ. 45)

Returns:: water stress factor
Return type:: numpy.ndarray

wdem()¶

RQ - 'water' from model with id 'crop.demand'

\(c_{\textrm{W-dem},k}\ [\frac{mm}{day}]\)

Returns:: water demand of crop
Return type:: Requirement

wupt()¶

RQ - 'water' from model with id 'crop.uptake'

\(c_{\textrm{W-up},k}\ [\frac{mm}{day}]\)

Returns:: uptake of water at current day
Return type:: Requirement