plants.plt

The plant growth database file stores information required to simulate plant growth by plant species.

The plant growth database distributed with SWAT+ includes parameters for most of the common plant species. If a user needs to model a land use or plant not included in the database, please feel free to contact the SWAT+ development team for assistance in determining plant parameters.

Field	Description	Type	Unit	Default	Range
name	Name of the plant/landcover	​string	​n/a	n/a	n/a
plnt_typ	Plant/landcover type	​string	n/a	n/a	n/a
gro_trig	Phenology trigger	string	n/a	n/a	n/a
nfix_co	Nitrogen fixation coefficient	real​	none	0.0	n/a
days_mat	Days to maturity	real	days	110.0	0.0-300.0
bm_e	Biomass-energy ratio	real	(kg/ha/(MJ/m^2)	15.0	10.0-90.0
harv_idx	Harvest index for optimal growth conditions	real	(kg/ha)/(kg/ha)	0.76	0.01-1.25
lai_pot	Maximum potential leaf area index	real	none	5.0	0.50-10.0
frac_hu1	Fraction of the growing season heat units corresponding to the 1st point on optimal leaf area development curve	real	fraction	0.05	0.0-1.0
lai_max1	Fraction of the maximum leaf area index corresponding to the 1st point on optimal leaf area development curve	real	fraction	0.05	0.0-1.0
frac_hu2	Fraction of the growing season heat units corresponding to the 2nd point on optimal leaf area development curve	real	fraction	0.40	0.0-1.0
lai_max2	Fraction of the maximum leaf area index corresponding to the 2nd point on optimal leaf area development curve	real	fraction	0.95	0.0-1.0
hu_lai_decl	Fraction of growing season when leaf area begins to decline	real	fraction	0.99	0.2-1.0
dlai_rate	Exponent that governs the LAI decline rate	real	n/a	1.0
can_ht_max	Maximum canopy height	real	m	6.0	0.1-20.0
rt_dp_max	Maximum rooting depth	real	m	3.50	0.0-3.0
tmp_opt	Optimal temperature for plant growth	real	deg c	30.0	11.0-38.0
tmp_base	Minimum temperature for plant growth	real	deg c	10.0	0.0-18.0
frac_n_yld	Normal fraction of N in yield	real	kg N/kg yield	0.0015	0.0015-0.075
frac_p_yld	Normal fraction of P in yield	real	kg P/kg yield	0.0003	0.0015-0.0075
frac_n_em	Normal fraction of N in plant biomass at emergence	real	kg N/kg biomass	0.006	0.004-0.07
frac_n_50	Normal fraction of N in plant biomass at 50% maturity	real	kg N/kg biomass	0.002	0.002-0.05
frac_n_mat	Normal fraction of N in plant biomass at maturity	real	kg N/kg biomass	0.0015	0.001-0.27
frac_p_em	Normal fraction pf P in plant biomass at emergence	real	kg P/kg biomass	0.0007	0.0005-0.01
frac_p_50	Normal fraction of P in plant at 50% maturity	real	kg P/kg biomass	0.0004	0.0002-0.007
frac_p_mat	Normal fraction of P in plant at maturity	real	kg P/kg biomass	0.0003	0.0003-0.0004
harv_idx_ws	Harvest index that represents the lowest harvest index expected due to water stress	real	(kg/ha)/(kg/ha)	0.01	-0.2-1.1
usle_c_min	Minimum value of the USLE C factor for water erosion	real	none	0.001	0.001-0.50
stcon_max	Maximum stomatal conductance	real	m/s	0.002	0.0-0.50
vpd	Vapor pressure deficit corresponding to the 2nd point on the stomatal conductance curve	real	kPa	4.0	1.5-6.0
frac_stcon	Fraction of maximum stomatal conductance corresponding to the 2nd point on the stomatal conductance curve	read	fraction	0.75	0.0-1.0
ru_vpd	Rate of decline in radiation use efficiency per unit increase in vapor pressure deficit	real	none	8.0	0.0-50.0
co2_hi	Elevated CO2 atmospheric concentration corresponding the 2nd point on the radiation use efficiency curve	real	μL CO2/L air	660.0	300.0-1000.0
bm_e_hi	Biomass-energy ratio corresponding to the 2nd point on the radiation use efficiency curve	real	(kg/ha)/(MJ/m^2)	16.0	5.0-100.0
plnt_decomp	Plant residue decomposition coefficient	real	none	0.05	0.01-0.099
lai_min	Minimum LAI during dormant period	real	m^2/m^2	0.75	0.00-0.99
bm_tree_acc	Fraction of biomass accumulated each year	real	fraction	0.30	0.0-1.0
yrs_mat	Years to maturity	integer	years	10	0-100
bm_tree_max	Maximum forest biomass	real	metric tons/ha	1000.0	0.0-5000.0
ext_co	Light extinction coefficient	real	none	0.65	0.0-2.0
leaf_tov_min	Perennial leaf turnover rate with minimum stress	real		12.0
leaf_tov_max	Perennial leaf turnover rate with maximum stress	real		3.0
bm_dieoff	Above-ground biomass that dies off at dormancy	real	fraction	1.0	0.0-1.0
rt_st_beg	Root to shoot ratio at the beginning of the growing season	real	fraction	0.
rt_st_end	Root to shoot ratio at the end of the growing season	real	fraction	0.
plnt_pop1	Plant population corresponding to the 1st point on the population LAI curve	real	plants/m^2	0.
frac_lai1	Fraction of the maximum leaf area index corresponding to the 1st point on the leaf area development curve	real	fraction	0.	0.0-1.0
plnt_pop2	Plant population corresponding to the 2nd point on the population LAI curve	real	plants/m^2	0.0
frac_lai2	Fraction of the maximum leaf area index corresponding to the 2nd point on the leaf area development curve	real	fraction	0.0	0.0-1.0
frac_sw_gro	Fraction of field capacity to initiate growth of tropical plants during monsoon season	real	fraction	0.5	0.0-1.0
aeration	Aeration stress factor	real		0.0
wnd_dead	Wind erosion factor for standing dead residue	real		0.0
wnd_flat	Wind erosion factor for flat residue	real		0.0