Figure 1.
Rainfall data during the test period. Blue bars indicate the rainfall that did not produce runoff, red bars indicate the rainfall that resulted in runoff, and black lines indicate cumulative rainfall depth.

Figure 1.
Rainfall data during the test period. Blue bars indicate the rainfall that did not produce runoff, red bars indicate the rainfall that resulted in runoff, and black lines indicate cumulative rainfall depth.

Figure 2.
Experimental area’s vertical layout. Plant layer: Sedum lineare Thunb.; substrate layer: mixture with a thickness of 10 cm; filter layer: geotextile with 150 g/m

2

; egg carton-like water storage and drainage layer: 25 mm thick molded polystyrene.

Figure 3.
Runoff quality indicators for different treatments. The different capital letters (A–F) indicate the statistical difference between different sampling times for the same treatment, and the different lowercase letters (a–e) indicate the statistical difference between different treatments at the same sampling time: (a) = pH, (b) = TN concentration, (c) = NO

3
?

concentration, (d) = TP concentration, (e) = orthophosphate concentration, and (f) = DOC concentration.

Figure 3.
Runoff quality indicators for different treatments. The different capital letters (A–F) indicate the statistical difference between different sampling times for the same treatment, and the different lowercase letters (a–e) indicate the statistical difference between different treatments at the same sampling time: (a) = pH, (b) = TN concentration, (c) = NO

3
?

concentration, (d) = TP concentration, (e) = orthophosphate concentration, and (f) = DOC concentration.

Figure 4.
Response relationship between the nutrient leaching and rainfall characteristics. (a,c,e) Relationship between TN concentration, TP concentration, DOC concentration, and cumulative rainfall depth. (b,d,f) Relationship between TN concentration, TP concentration, DOC concentration, and single rainfall depth.

Figure 4.
Response relationship between the nutrient leaching and rainfall characteristics. (a,c,e) Relationship between TN concentration, TP concentration, DOC concentration, and cumulative rainfall depth. (b,d,f) Relationship between TN concentration, TP concentration, DOC concentration, and single rainfall depth.

Table 1.
The proportion of each component in the substrate (v/v).

TreatmentSoilBiocharPerliteVermiculiteCK70%015%15%MS1060%10%15%15%MS1555%15%15%15%MS2050%20%15%15%RH1060%10%15%15%RH1555%15%15%15%RH2050%20%15%15%

Table 2.
Chemical properties of the components (“-” means below the detection limit).

ComponentpHTC (g kg

?
1

)TN (g kg

?
1

)TP (g kg

?
1

)Soil8.012.12.11.5MSB10.4470.412.012.7RHB8.5390.19.91.4Perlite7.0—Vermiculite7.0—

Table 3.
Results of two-way repeat measures ANOVA.

IndicatorspHTNNO

3
?

TPOrthophosphate
DOC Fp

?

p
2

Fp

?

p
2

Fp

?

p
2

Fp

?

p
2

Fp

?

p
2

Fp

?

p
2

Treatment16.76<0.0010.88104.05<0.0010.98121.05<0.0010.98127.33<0.0010.98445.30<0.0010.99105.90<0.0010.98Time53.51<0.0010.79271.15<0.0010.95268.09<0.0010.954.020.030.2211.50<0.0010.4573.25<0.0010.80Interaction3.74<0.0010.6250.73<0.0010.9650.36<0.0010.961.650.130.4110.01<0.0010.8116.17<0.0010.87