Table S1 Major Chemical Characteristics of the Mine Spoil Used for the Experiment

Supporting Information

1.Supplementary Tables

Table S1 Major chemical characteristics of the mine spoil used for the experiment

Parameter / Mine spoil / Method
Organic matter content (%) / 0.54 / Walkley–Black method
Mineral composition / Jarosite (28%), gypsum (27%), quartz (25%), feldspar (6%), elemental S (4%), anglesite (4%) / XRD
MgO（%） / 0.65 / XRF
Al2O3（%） / 6.96
SiO2（%） / 33.3
SO3（%） / 27.8
K2O（%） / 2.86
CaO（%） / 8.70
PbO（%） / 3.41
MnO（%） / 0.02
Fe2O3（%） / 14.7
CuO（%） / 0.31
ZnO（%） / 0.25
Water-extractable K (mg/kg) / 2.03 / 1:5 water extract,measured by AAS
Water-extractable Na (mg/kg) / 9.02
Water-extractable Ca (mg/kg) / 2846
Water-extractable Mg (mg/kg) / 28.1
Water-extractable Fe (mg/kg) / 35.7
Water-extractable Mn (mg/kg) / 5.12
Water-extractable Cu (mg/kg) / 9.99
Water-extractable Zn (mg/kg) / 26.9
Water-extractable Pb (mg/kg) / 18.2
Water-extractable Cd (mg/kg) / 0.45
Water-extractable Cr (mg/kg) / 0.04
NH4Cl-extractable K (mg/kg) / 5.97 / 1:5 NH4Cl extract,measured by AAS
NH4Cl-extractable Na (mg/kg) / 10.5
NH4Cl-extractable Ca (mg/kg) / 8574
NH4Cl-extractable Mg (mg/kg) / 23.6
NH4Cl-extractable Fe (mg/kg) / 71.8
NH4Cl-extractable Mn (mg/kg) / 4.98
NH4Cl-extractable Cu (mg/kg) / 13.7
NH4Cl-extractable Zn (mg/kg) / 30.4
NH4Cl-extractable Pb (mg/kg) / 869
NH4Cl-extractable Cd (mg/kg) / 0.77
NH4Cl-extractable Cr (mg/kg) / 0.06

Table S2 Some elements contained in the straw clippings used for the incubation experiment

Element / Average / SD (n=3)
Zn (mg kg-1) / 43.8 / 0.23
Cd (mg kg-1) / 0.41 / 0.10
Cu (mg kg-1) / 10.3 / 0.44
Pb (mg kg-1) / 1.25 / 0.17
P (g kg-1) / 0.71 / 0.03
N (g kg-1) / 30.5 / 2.81
K (g kg-1) / 33.6 / 0.03

2.Supplementary Figure

The Control (C)

Treatment 1 (T1)

Treatment 2 (T2)

Figure S1 Schematic diagram showing the experimental apparatus for the incubation experiment