Modeling Phosphorus Capture by Plants Growing in a Multispecies Riparian Buffer

Table 3

Transport, sorption, and root parameters used in the NST 3.0 model to describe P uptake by smooth brome for the 0–120, 0–30, 30–60, and 60–120 cm soil depths.

Parameter		Units	0–120 cm	0–30 cm	30–60 cm	60–120 cm
𝐷𝑒	Diffusion coefficient in water^†	cm^2 s^−1	8.9𝐸−6	8.9𝐸−6	8.9𝐸−6	8.9𝐸−6
Θ	Volumetric soil water content	cm^3 H2O/cm^3 soil	0.256	0.25	0.26	0.26
𝑓	Impedance factor	Unitless	0.243	0.23	0.25	0.25
𝑉𝑜	Water uptake at root	cm s^−1	8.16𝐸−7	8.16𝐸−7	8.16𝐸−7	8.16𝐸−7
𝐶li	Initial solution concentration	𝜇mol cm^−3	1.141𝐸−2	3.74𝐸−2	2.58𝐸−3	2.58𝐸−3
𝑏	Buffer power	Unitless	73	28	98	92
𝐼max	Maximum influx at high concentration	𝜇mol cm^−2 s^−1	3.27𝐸−8	3.27𝐸−8	3.27𝐸−8	3.27𝐸−8
𝐾𝑚	Solution concentration when influx is 0.5 𝐼max	𝜇mol cm^−3	2.71𝐸−5	2.71𝐸−5	2.71𝐸−5	2.71𝐸−5
𝐶min	Solution concentration when influx is zero	𝜇mol cm^−3	1.22𝐸−6	1.22𝐸−6	1.22𝐸−6	1.22𝐸−6
𝑟𝑜	Root radius	cm	0.0114	0.0135	0.009	0.0117
𝑟1	Half distance	cm	0.505	0.255	0.347	0.914
𝐿𝑜	Initial root length	cm m^−3	2,486,379	1,464,477	793,155	228,747
𝑘	Root growth rate	cm d^−1	3,572	8,631	1,622	464

^†From Edwards and Huffman [18].