# -*- coding: utf-8 -*-
# Copyright (c) 2004-2024 Wageningen Environmental Research, Wageningen-UR
# Allard de Wit (allard.dewit@wur.nl), March 2024
from pcse.traitlets import Float
from pcse.decorators import prepare_rates, prepare_states
from pcse.base import ParamTemplate, StatesTemplate, RatesTemplate, \
SimulationObject
from pcse import signals
class N_PotentialProduction(SimulationObject):
"""Provides unlimited soil N/P/K for potential production simulations.
NAVAIL just remains 100 kg/ha whatever the crop takes.
"""
class StateVariables(StatesTemplate):
NAVAIL = Float(-99.) # total mineral N from soil and fertiliser kg N ha-1
def initialize(self, day, kiosk, parvalues):
"""
:param day: start date of the simulation
:param kiosk: variable kiosk of this PCSE instance
:param cropdata: dictionary with WOFOST cropdata key/value pairs
"""
self.states = self.StateVariables(kiosk, publish=["NAVAIL"], NAVAIL=100.)
def calc_rates(self, day, drv):
pass
@prepare_states
def integrate(self, day, delt=1.0):
self.touch()
[docs]class N_Soil_Dynamics(SimulationObject):
"""A simple module for soil N dynamics.
This modules represents the soil as a bucket for available N consisting
of two components: 1) a native soil supply which consists of an initial
amount of N which will become available with a fixed fraction every day
and 2) an external supply which is computed as an amount of N supplied
and multiplied by a recovery fraction in order to have an effective amount of
N that is available for crop growth.
This module does not simulate any soil physiological processes and is only
a book-keeping approach for N availability. On the other hand, it
requires no detailed soil parameters. Only an initial soil amount, the
fertilizer inputs, a recovery fraction and a background supply.
**Simulation parameters**
============ ============================================= ======= ==============
Name Description Type Unit
============ ============================================= ======= ==============
NSOILBASE Base soil supply of N available through SSi |kg ha-1|
mineralisation
NSOILBASE_FR Fraction of base soil N that comes available SSi -
every day
NAVAILI Initial N available in the N pool SSi |kg ha-1|
BG_N_SUPPLY Background supply of N through atmospheric SSi |kg ha-1 d-1|
deposition.
============ ============================================= ======= ==============
**State variables**
======= ================================================= ==== ============
Name Description Pbl Unit
======= ================================================= ==== ============
NSOIL total mineral soil N available at start of N [kg ha-1]
growth period
NAVAIL Total mineral N from soil and fertiliser Y |kg ha-1|
======= ================================================= ==== ============
**Rate variables**
============== ================================================= ==== =============
Name Description Pbl Unit
============== ================================================= ==== =============
RNSOIL Rate of change on total soil mineral N N |kg ha-1 d-1|
RNAVAIL Total change in N availability N |kg ha-1 d-1|
# Rate of fertilizer supply for N/P/K [kg/ha/day]
FERT_N_SUPPLY Supply of fertilizer N. This will be supplied N |kg ha-1 d-1|
by the AgroManager module through the event
mechanism. See the section on signals below.
============== ================================================= ==== =============
**Signals send or handled**
`N_Soil_Dynamics` receives the following signals:
* APPLY_N: Is received when an external input from N fertilizer
is provided. See `_on_APPLY_N()` for details.
**External dependencies:**
========= =================================== =================== ==============
Name Description Provided by Unit
========= =================================== =================== ==============
DVS Crop development stage DVS_Phenology -
TRA Actual crop transpiration Evapotranspiration |cm|
increase
TRAMX Potential crop transpiration Evapotranspiration |cm|
increase
RNuptake Rate of N uptake by the crop NPK_Demand_Uptake |kg ha-1 d-1|
========= =================================== =================== ==============
"""
NSOILI = Float(-99.) # initial soil N amount
class Parameters(ParamTemplate):
NSOILBASE = Float(-99.) # total mineral soil N available at start of growth period [kg N/ha]
NSOILBASE_FR = Float(-99.) # fraction of soil mineral N coming available per day [day-1]
NAVAILI = Float()
BG_N_SUPPLY = Float()
class StateVariables(StatesTemplate):
NSOIL = Float(-99.) # mineral N available from soil for crop kg N ha-1
NAVAIL = Float(-99.) # total mineral N from soil and fertiliser kg N ha-1
class RateVariables(RatesTemplate):
RNSOIL = Float(-99.)
RNAVAIL = Float(-99.)
# Rate of fertilizer supply for N [kg/ha/day]
FERT_N_SUPPLY = Float()
def initialize(self, day, kiosk, parvalues):
"""
:param day: start date of the simulation
:param kiosk: variable kiosk of this PCSE instance
:param cropdata: dictionary with WOFOST cropdata key/value pairs
"""
self.params = self.Parameters(parvalues)
self.rates = self.RateVariables(kiosk)
self.kiosk = kiosk
# INITIAL STATES
p = self.params
self.NSOILI = p.NSOILBASE
self.states = self.StateVariables(kiosk,
publish=["NAVAIL"], NSOIL=p.NSOILBASE, NAVAIL=p.NAVAILI)
self._connect_signal(self._on_APPLY_N, signals.apply_n)
@prepare_rates
def calc_rates(self, day, drv):
r = self.rates
s = self.states
p = self.params
k = self.kiosk
r.RNSOIL = -max(0., min(p.NSOILBASE_FR * self.NSOILI, s.NSOIL))
# Check uptake rates from crop, if a crop is actually growing
RNuptake = k.RNuptake if "RNuptake" in self.kiosk else 0.
r.RNAVAIL = r.FERT_N_SUPPLY + p.BG_N_SUPPLY - RNuptake - r.RNSOIL
@prepare_states
def integrate(self, day, delt=1.0):
rates = self.rates
states = self.states
# mineral N amount in the soil
states.NSOIL += rates.RNSOIL * delt
# total (soil + fertilizer) N amount in soil
states.NAVAIL += rates.RNAVAIL * delt
def _on_APPLY_N(self, N_amount=None,N_recovery=None):
r = self.rates
r.unlock()
r.FERT_N_SUPPLY = N_amount * N_recovery
r.lock()