crop module

Crop growth and yield module.

Model oil palm growth and yield.

Author - Christopher Teh Boon Sung

Contents namedtuple

Contents(n, m)

namedtuple: Nitrogen and minerals contents in a given plant part

n

float: N content

m

float: minerals content

Parts namedtuple

Parts(pinnae, rachis, trunk, roots, maleflo, femaflo, bunches)

namedtuple: Plant parts of the oil palm tree

pinnae

(Part): pinnae part

rachis

(Part): rachis part

trunk

(Part): trunk part

roots

(Part): roots parts

maleflo

(Part): male flowers part

femaflo

(Part): female flowers parts

bunches

(Part): bunches part

Part class

Class for individual plant parts (e.g., pinnae, rachis, trunk, etc.).

ATTRIBUTES

content (Contents): N and mineral content (each stored as an AFGen object)
maint (float): Assimilates used for maintenance (kg CH2O/palm/day)
frac (float): DM (dry matter) partitioning (fraction)
growth (float): Growth rate (kg DM/palm/day)
death (float): Death rate (kg DM/palm/day)
weight (float): Weight of the plant part (kg DM/palm)

Constructor init

Part(self)

Create and initialize the Part object.

Crop class

Crop class (oil palm growth and yield).

EXTERNAL INFORMATION REQUIRED (MUST BE SUPPLIED FROM AN EXTERNAL CLASS):

    assimilates (float): Total amount of assimilates from photosynthesis
                         (kg CH2O/palm/day)
    cropstress (float): Plant water stress level
                        (0 = max. stress to 1 = no stress)

ATTRIBUTES

treeage (int): Age of the tree (days)
plantdens (int): Planting density (palms/ha)
thinplantdens (int): Thinning planting density (palms/ha)
thinage (int): Thinning tree age (days)
femaleprob (float): Probability of obtaining female flowers (fraction)
parts (Parts): Parts namedtuple of the various plant parts
slatable (AFGen): SLA table (age vs SLA)
trunkhgt (float): Trunk height (m)
treehgt (float): Total tree height (m)
vdmwgt (float): VDM (vegetative dry matter) weight (kg DM/palm)
tdmwgt (float): Total DM weight (kg DM/palm)
vdmmax (float): Maximum VDM requirement for the given planting density (kg DM/palm/year)
laimax (float): Maximum LAI (leaf area index) (m2 leaf/m2 ground)
sla (float): SLA (specific leaf area) (m2 leaf/kg leaf)
lai (float): LAI (leaf area index) (m2 leaf/m2 ground)
vdmreq (float): VDM demand for growth (kg DM/palm/day)
assim4maint (float): Total maintenance (kg CH2O/palm/day)
assim4growth (float): Assimilates for vegetative growth (kg CH2O/palm/day)
assim4gen (float): Assimilates for generative growth (kg CH2O/palm/day)
boxmaleflo (list): Boxcar for male flowers
boxfemaflo (list): Boxcar for female flowers (immature bunches)
boxbunches (list): Boxcar for mature bunches
bunchyield (float): Yield (kg DM/palm/year)
flowersex (int): Flower sex at the start of bunch/mature phase (0 = male/abort, 1 = female)
newflowersex (int): Sex of new flower (0 = male/abort, 1 = female)

METHODS

tree_height: Trunk and total tree height (canopy + trunk height) (m)
dm_wgts: Weight of vegetative parts and all parts (kg DM/palm)
vdm_maximum: Maximum VDM requirement for the given planting density (kg DM/palm/year)
lai_maximum: Maximum LAI for the given planting density (m2 leaf/m2 ground)
lookup_sla_lai: SLA-LAI lookup table
maintenance_respiration: Maintenance requirement for every plant part (kg CH2O/palm/day)
vdm_requirement: Calculate the required VDM for growth (kg DM/palm/YEAR)
veg_partitioning: DM partitioning for the various plant parts (fraction)
cvf: Convert weight in glucose, CH2O, to that in dry matter, DM (kg DM/kg CH2O)
veg_growth_rates: Growth rates for the various plant parts (kg DM/palm/day)
veg_death_rates: Death rates for the various plant parts (kg DM/palm/day)
update_veg_weights: Increment the various plant parts (kg DM/palm)
new_flower_sex: Determine the gender of the first (newest) flower in the "boxcar"
gen_growth_rates: Growth rates for generative organs (kg DM/palm/day)
update_gen_weights: Increment the weights for all generative organs (kg DM/palm)
daily_growth: Solve for the crop growth and yield
doy_has_changed: Day of year has changed, so update crop properties
update: Calls the daily_growth() method

Constructor init

Crop(self, fname_in)

Create and initialize the Crop object.

Arguments

fname_in (str): path and filename of the model initialization file

tree_height

Crop.tree_height(self, cropstress)

Trunk and total tree height (canopy + trunk height) (m).

Arguments

cropstress (float): 0-1 plant water stress; 0 = max stress, 1 = no stress

Returns

tuple: trunk and total tree height (float)

dm_wgts

Crop.dm_wgts(self)

Weight of vegetative parts and all parts (kg DM/palm).

Returns

tuple: VDM and TDM (float)

vdm_maximum

Crop.vdm_maximum(self)

Maximum VDM requirement for the given planting density (kg DM/palm/year).

Returns

float: max VDM

lai_maximum

Crop.lai_maximum(self)

Maximum LAI for the given planting density (m2 leaf/m2 ground).

Returns

float: maximum LAI

lookup_sla_lai

Crop.lookup_sla_lai(self)

SLA-LAI lookup table.

Lookup from AFGen the current SLA (specific leaf area, m2 leaf/kg leaf) then calculate the LAI (m2 leaf/m2 ground).

Returns

tuple: SLA and LAI (float)

maintenance_respiration

Crop.maintenance_respiration(self, assimilates)

Maintenance requirement for every plant part (kg CH2O/palm/day).

Arguments

assimilates (float): amount of assimilates from photosynthesis (kg CH2O/palm/day)

Returns

tuple: maintenance for every plant part (float)

vdm_requirement

Crop.vdm_requirement(self)

Calculate the required VDM for growth (kg DM/palm/YEAR).

VDM is per annual basis, so don't forget to divide by 365 to obtain the required VDM per DAY.

Returns

float: VDM

veg_partitioning

Crop.veg_partitioning(self)

DM partitioning for the various plant parts (fraction).

Returns

tuple: DM partitioning between all plant parts(float)

cvf

Crop.cvf(self)

Convert weight in glucose, CH2O, to that in dry matter, DM (kg DM/kg CH2O).

Returns

float: conversion factor

veg_growth_rates

Crop.veg_growth_rates(self)

Growth rates for the various plant parts (kg DM/palm/day).

Returns

tuple: growth rates (float)

veg_death_rates

Crop.veg_death_rates(self)

Death rates for the various plant parts (kg DM/palm/day).

Returns

tuple: death rates (float)

update_veg_weights

Crop.update_veg_weights(self, assimilates)

Increment the various plant parts (kg DM/palm).

Arguments

assimilates (float): amount of assimilates from photosynthesis (kg CH2O/palm/day)

Returns

None:

new_flower_sex

Crop.new_flower_sex(self)

Determine the gender of the first (newest) flower in the "boxcar".

Returns

int: sex of flower (0 = male/abortl 1 = female)

gen_growth_rates

Crop.gen_growth_rates(self)

Growth rates for generative organs (kg DM/palm/day).

Returns

tuple: generative growth rates (float)

update_gen_weights

Crop.update_gen_weights(self, cropstress)

Increment the weights for all generative organs (kg DM/palm).

Arguments

cropstress (float): 0-1 plant water stress; 0 = max stress, 1 = no stress

Returns

None:

daily_growth

Crop.daily_growth(self, assimilates, cropstress)

Solve for the crop growth and yield.

Arguments

assimilates (float): amount of assimilates from photosynthesis (kg CH2O/palm/day)
cropstress (float): 0-1 plant water stress; 0 = max stress, 1 = no stress

Returns

None:

doy_has_changed

Crop.doy_has_changed(self)

DOY has changed, so change the tree age.

Returns

None:

update

Crop.update(self, external_info)

Update the crop properties by calling the daily_growth method.

Arguments

external_info (dict): requires information on the assimilates and crop stress level

Returns

None:

crop module

Contents namedtuple

n

m

Parts namedtuple

pinnae

rachis

trunk

roots

maleflo

femaflo

bunches

Part class

Constructor __init__

Crop class

Constructor __init__

tree_height

dm_wgts

vdm_maximum

lai_maximum

lookup_sla_lai

maintenance_respiration

vdm_requirement

veg_partitioning

cvf

veg_growth_rates

veg_death_rates

update_veg_weights

new_flower_sex

gen_growth_rates

update_gen_weights

daily_growth

doy_has_changed

update

Constructor init

Constructor init