This is a post-peer-review, pre-copyedit version of the supplementary information of an article published in Environmental geochemistry and health (Ed. Springer). The final authenticated version is available online at: DOI 10.1007/s10653-018-0224-7 1 Supplementary Information 2 3 4 Table S1 5 Characteristics of the steel slag and biochar used in the study. Amendment Physical Fe2O3 Fe S SiO2 C N P K Mg Ca property (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Steel slag Granular form 4.8 - - 40.7 0.7 0.01 0.01 0.5 0.36 24.9 (2 mm) Biochar Granular form - 0.2 0.6 - 56.6 1.4 1.0 1.8 1.0 0.5 (2 mm) 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 1 27 28 29 Table S2 30 Summary of the RM-ANOVAs for GHG emissions of the various amendments. Early paddy CO2 df MS F P Steel slag 1, 4 54059.92 0.19 0.688 Time 13, 52 7524128.53 67.93 <0.001 Steel slag × Time 13, 52 104494.18 0.943 0.517 Biochar 1, 4 317787.73 0.53 0.506 Time 13, 52 7208353.39 59.72 <0.001 Biochar × Time 13, 52 59643.70 0.49 0.918 Steel slag+biochar 1, 4 1138345.45 7.46 0.052 Time 13, 52 6998406.21 70.89 <0.001 Steel slag+biochar × Time 13, 52 79509.02 0.85 0.652 Late paddy CO2 Steel slag 1, 4 585763.22 13.93 0.020 Time 15, 60 3029441.01 94.78 <0.001 Steel slag × Time 15, 60 109590.67 3.43 <0.001 Biochar 1, 4 2507948.12 14.75 0.018 Time 15, 60 2511364.61 96.83 <0.001 Biochar × Time 15, 60 134246.53 5.18 <0.001 Steel slag+biochar 1, 4 32918.24 7.87 0.048 Time 15, 60 2448082.17 53.77 <0.001 Steel slag+biochar × Time 15, 60 85507.06 1.88 0.044 Early paddy CH4 Steel slag 1, 4 2.021 1.312 0.316 Time 13, 52 73.84 34.66 <0.001 Steel slag × Time 13, 52 3.01 1.41 0.186 Biochar 1, 4 0.85 0.07 0.801 Time 13, 52 87.31 19.39 <0.001 Biochar × Time 13, 52 2.27 0.50 0.912 Steel slag+biochar 1, 4 21.14 32.57 0.005 Time 13, 52 54.93 27.52 <0.001 2 Steel slag+biochar × Time 13, 52 4.18 2.09 0.031 Late paddy CH4 Steel slag 1, 4 25.38 0.37 0.578 Time 15, 60 711.01 33.36 <0.001 Steel slag × Time 15, 60 64.49 3.03 0.001 Biochar 1, 4 221.51 1.07 0.359 Time 15, 60 537.83 10.23 <0.001 Biochar × Time 15, 60 70.97 1.35 0.203 Steel slag+biochar 1, 4 130.08 2.28 0.206 Time 15, 60 621.80 17.97 <0.001 Steel slag+biochar × Time 15, 60 68.66 1.98 0.032 Early paddy N2O Steel slag 1, 4 5076.14 0.45 0.540 Time 13, 52 32448.60 2.85 0.004 Steel slag × Time 13, 52 2779.58 0.24 0.996 Biochar 1, 4 1538.32 0.12 0.747 Time 13, 52 39257.66 4.83 <0.001 Biochar × Time 13, 52 5510.67 0.68 0.775 Steel slag+biochar 1, 4 2737.72 0.24 0.648 Time 13, 52 19283.65 2.73 0.005 Steel slag+biochar × Time 13, 52 8281.25 1.17 0.324 Late paddy N2O Steel slag 1, 4 11686.97 6.56 0.063 Time 15, 60 3818.05 1.47 0.146 Steel slag × Time 15, 60 3448.02 1.33 0.215 Biochar 1, 4 41878.19 11.01 0.029 Time 15, 60 9255.20 2.98 0.001 Biochar × Time 15, 60 4159.39 1.34 0.209 Steel slag+biochar 1, 4 22543.45 10.36 0.032 Time 15, 60 5042.87 2.05 0.026 Steel slag+biochar × Time 15, 60 2958.56 1.21 0.294 31 32 3 33 34 35 Table S3 36 Summary of the mixed models. Variable Model Treatment Total model (R2m=Fixed, R2c=Fixed+ random) Early paddy over time Salinity F=89.0, P<0.0001 R2m=0.30, R2c=0.81 Soil water content F=8176, P<0.0001 R2m=0.57, R2c=0.82 Soil temperature F=0.80, P=0.50 R2m=0.00023, R2c=0.98 Soil pH F=93.8, P<0.0001 R2m=0.58, R2c=0.65 CO2 emissions F=4.36, P=0.0059 R2m=0.0059, R2c=0.92 CH4 emissions F=4.01, P=0.0093 R2m=0.016, R2c=0.78 N2O emissions F=0.28, P=0.84 R2m=0.0033, R2c=0.34 Late paddy over time Salinity F=43.9, P<0.0001 R2m=0.16, R2c=0.77 Soil water content F=153, P<0.0001 R2m=0.33, R2c=0.86 Soil temperature F=4.079, P=0.0082 R2m=0.00013, R2c=0.998 Soil pH F=284, P<0.0001 R2m=0.79, R2c=0.83 CO2 emissions F=15.74, P<0.0001 R2m=0.031, R2c=0.87 CH4 emissions F=1.59, P=0.19 R2m=0.0104, R2c=0.58 N2O emissions F=5.34, P=0.0016 R2m=0.057, R2c=0.32 Total emissions early paddy CO2 emissions F=1.1038, P=0.42 R2m=0.23, R2c=0.24 CH4 emissions F=3.78, P=0.033 R2m=0.33, R2c=0.56 N2O emissions F=0.29, P=0.83 R2m=0.064, R2c=0.20 Total emissions early paddy CO2 emissions F=8.68, P=0.0133 R2m=0.70, R2c=0.71 CH4 emissions F=0.56, P=0.66 R2m=0.13, R2c=0.13 N2O emissions F=0.29, P=0.83 R2m=0.064, R2c=0.20 Total emissions early + late paddy CO2 emissions F=8.68, P=0.0133 R2m=0.70, R2c=0.71 4 CH4 emissions F=0.56, P=0.66 R2m=0.13, R2c=0.13 N2O emissions F=0.74, P=0.57 R2m=0.17, R2c=0.16 Total emissions by yield in early paddy (kg CO2-eq mg-1 yield) CO2 emissions F=1.104, P=0.42 R2m=0.23, R2c=0.24 CH4 emissions F=2.80, P=0.13 R2m=0.33, R2c=0.56 N2O emissions F=0.33, P=0.80 R2m=0.23, R2c=0.70 Total emissions by yield in late paddy (kg CO2-eq mg-1 yield) CO2 emissions F=8.68, P=0.013 R2m=0.70, R2c=0.71 CH4 emissions F=0.56, P=0.66 R2m=0.13, R2c=0.14 N2O emissions F=0.33, P=0.80 R2m=0.07, R2c=0.23 Total emissions by yield in early + late paddy (kg CO2-eq mg-1 yield) CO2 emissions F=6.01, P=0.031 R2m=0.62, R2c=0.62 CH4 emissions F=0.74, P=0.57 R2m=0.17, R2c=0.18 N2O emissions F=0.33, P=0.80 R2m=0.07, R2c=0.23 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 5 56 57 58 59 Table S4 60 Summary of the RM-ANOVAs for the soil properties of the various amendments. Early paddy df MS F P pH Steel slag 1, 4 20.34 604.17 <0.001 Time 13, 52 0.47 46.97 <0.001 Steel slag × Time 13, 52 0.23 23.16 <0.001 Biochar 1, 4 3.64 357.20 <0.001 Time 13, 52 0.20 56.59 <0.001 Biochar × Time 13, 52 0.05 14.83 <0.001 Steel slag+biochar 1, 4 29.10 199.75 <0.001 Time 13, 52 0.32 3.10 0.002 Steel slag+biochar × Time 13, 52 0.42 4.05 <0.001 Salinity Steel slag 1, 4 0.94 54.35 0.002 Time 13, 52 0.11 31.69 <0.001 Steel slag × Time 13, 52 0.01 3.22 0.001 Biochar 1, 4 1.36 250.20 <0.001 Time 13, 52 0.15 42.15 <0.001 Biochar × Time 13, 52 0.02 6.37 <0.001 Steel slag+biochar 1, 4 2.34 46.89 0.002 Time 13, 52 0.15 23.88 <0.001 Steel slag+biochar × Time 13, 52 0.03 4.74 <0.001 Temperature Steel slag 1, 4 0.10 0.61 0.477 Time 13, 52 46.80 502.13 <0.001 Steel slag × Time 13, 52 0.32 3.40 0.001 Biochar 1, 4 468.60 0.98 0.379 Time 13, 52 612.11 1.28 0.257 Biochar × Time 13, 52 481.87 1.01 0.461 6 Steel slag+biochar 1, 4 0.27 1.01 0.373 Time 13, 52 49.07 524.01 <0.001 Steel slag+biochar × Time 13, 52 0.15 1.63 0.107 Water content Steel slag 1, 4 2413.93 121.08 <0.001 Time 13, 52 316.70 53.49 <0.001 Steel slag × Time 13, 52 13.16 2.22 0.021 Biochar 1, 4 15438.87 76.21 0.001 Time 13, 52 560.17 13.57 <0.001 Biochar × Time 13, 52 141.69 3.43 0.001 Steel slag+biochar 1, 4 24802.42 888.35 <0.001 Time 13, 52 549.07 27.81 <0.001 Steel slag+biochar × Time 13, 52 134.52 6.81 <0.001 Late paddy pH Steel slag 1, 4 37.23 965.30 <0.001 Time 15, 60 0.15 5.75 <0.001 Steel slag × Time 15, 60 0.16 5.84 <0.001 Biochar 1, 4 9.81 557.36 <0.001 Time 15, 60 0.13 8.28 <0.001 Biochar × Time 15, 60 0.16 10.44 <0.001 Steel slag+biochar 1, 4 40.68 2956.32 <0.001 Time 15, 60 0.11 2.80 0.002 Steel slag+biochar × Time 15, 60 0.13 3.25 0.001 Salinity Steel slag 1, 4 1.02 118.96 <0.001 Time 15, 60 0.17 21.76 <0.001 Steel slag × Time 15, 60 0.02 2.89 0.002 Biochar 1, 4 0.72 36.50 0.004 Time 15, 60 0.20 52.96 <0.001 Biochar × Time 15, 60 0.01 3.32 <0.001 Steel slag+biochar 1, 4 0.73 70.37 0.001 Time 15, 60 0.16 27.73 <0.001 7 Steel slag+biochar × Time 15, 60 0.02 3.50 <0.001 Temperature Steel slag 1, 4 0.18 1.15 0.34 Time 15, 60 85.67 2445.63 <0.001 Steel slag × Time 15, 60 0.06 1.56 0.11 Biochar 1, 4 0.11 0.70 0.451 Time 15, 60 84.47 2214.68 <0.001 Biochar × Time 15, 60 0.03 0.82 0.650 Steel slag+biochar 1, 4 0.30 1.97 0.234 Time 15, 60 84.32 2354.94 <0.001 Steel slag+biochar × Time 15, 60 0.06 1.68 0.080 Water content Steel slag 1, 4 2579.85 109.89 <0.001 Time 15, 60 750.25 105.44 <0.001 Steel slag × Time 15, 60 52.96 7.44 <0.001 Biochar 1, 4 7246.42 138.92 <0.001 Time 15, 60 565.37 87.96 <0.001 Biochar × Time 15, 60 53.73 8.36 <0.001 Steel slag+biochar 1, 4 8752.77 308.18 <0.001 Time 15, 60 451.36 31.66 <0.001 Steel slag+biochar × Time 15, 60 39.68 2.78 0.003 61 62 63 64 65 66 67 68 69 70 71 72 8 73 74 75 76 Table S5 77 Correlations between the soil properties and the GHG emissions. Early paddy CO2 CH4 N2O pH Salinity Temperature Water content Control (n=42) -0.148 0.435** -0.209 -0.510** 0.776** -0.610** Steel slag (n=42) -0.163 0.122 -0.251 -0.220 0.755** -0.449** Biochar (n=42) -0.213 0.201 -0.484** -0.354* 0.750** -0.617** Steel slag+biochar (n=42) -0.219 0.454** -0.043 -0.319* 0.727** -0.601** Total (n=168) -0.172* 0.275** -0.158* -0.310** 0.749** -0.416** CH4 CO2 N2O pH Salinity Temperature Water content Control (n=42) -0.148 -0.190 0.627** 0.560** -0.005 0.530** Steel slag (n=42) -0.163 -0.127 0.489** 0.614** -0.035 0.660** Biochar (n=42) -0.213 0.046 0.505** 0.587** -0.160 0.230 Steel slag+biochar (n=42) -0.219 -0.260* -0.163 0.614** 0.004 0.265* Total (n=168) -0.172* -0.101 0.086 0.420** -0.055 0.172* N2O CO2 CH4 pH Salinity Temperature Water content Control (n=42) 0.435** -0.190 -0.134 -0.325* 0.205 -0.279* Steel slag (n=42) 0.122 -0.127 -0.103 0.026 0.049 -0.221 Biochar (n=42) 0.201 0.046 0.136 -0.015 -0.079 0.062 Steel slag+biochar (n=42) 0.454** -0.260* 0.021 -0.058 0.111 -0.295* Total (n=168) 0.275** -0.101 -0.058 -0.087 0.075 -0.098 Late paddy CO2 CH4 N2O pH Salinity Temperature Water content Control (n=48) -0.483** -0.006 -0.318* -0.235 -0.205 -0.293* Steel slag (n=48) -0.400** -0.171 0.240 0.011 -0.357** -0.327* Biochar (n=48) -0.026 -0.124 0.170 0.102 -0.211 -0.159 Steel slag+biochar (n=48) -0.229 0.032 0.141 0.017 -0.175 -0.144 Total (n=192) -0.271** -0.028 -0.052 -0.085 -0.237** -0.294** CH4 CO2 N2O pH Salinity Temperature Water content Control (n=48) -0.483** -0.119 0.159 0.813** 0.736** 0.828** 9 Steel slag (n=48) -0.400** -0.130 -0.302* 0.609** 0.624** 0.727** Biochar (n=48) -0.026 -0.082 -0.106 0.596** 0.421** 0.594** Steel slag+biochar (n=48) -0.229 -0.037 -0.330* 0.407** 0.512** 0.380** Total (n=192) -0.271** -0.063 -0.119* 0.535** 0.575** 0.466** N2O CO2 CH4 pH Salinity Temperature Water content Control (n=48) -0.006 -0.119 0.176 -0.258* -0.206 -0.274* Steel slag (n=48) -0.171 -0.130 -0.009 -0.165 -0.175 -0.169 Biochar (n=48) -0.124 -0.082 -0.156 -0.227 -0.305* -0.186 Steel slag+biochar (n=48) 0.032 -0.037 -0.145 -0.150 -0.341** -0.217 Total (n=192) -0.028 -0.063 -0.159* -0.260** -0.249** -0.290** 78 *, significant at the 0.05 level; **, significant at the 0.01 level. 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 10 101 102 103 104 Table S6 105 Test statistics for squared Mahalanobis distances among the plots receiving the 106 fertilization treatments, with soil pH, temperature, salinity and water content and CO2, 107 CH4 and N2O emissions during the sampling period as independent continuous 108 variables and with sampling time as the categorical independent variable for the late 109 paddy crop. Mah, squared Mahalanobis distance. 110 Steel slag Biochar Steel+biochar Mah=41.2 Mah=28.0 Mah=60.0 Control F=39.9 F=27.1 F=58.2 P<0.0001 P<0.0001 P<0.0001 Mah=9.44 Mah=5.09 Steel slag F=9.15 F=4.93 P<0.0001 P<0.0001 Mah=10.2 Biochar F=9.92 P<0.0001 111 112 113 114 115 116 117 118 119 120 121 122 123 11 124 125 126 127 128 Table S7 129 Test statistics for squared Mahalanobis distances among the plots receiving the 130 fertilization treatments, with soil pH, temperature, salinity and water content and CO2, 131 CH4 and N2O emissions during the sampling period as independent continuous 132 variables and with sampling time as the categorical independent variable for the early 133 paddy crop. Mah, squared Mahalanobis distance. Steel slag Biochar Steel+biochar Mah=10.3 Mah=15.9 Mah=32.8 Control F=10.2 F=15.7 F=32.3 P<0.0001 P<0.0001 P<0.0001 Mah=10.9 Mah=11.9 Steel slag F=10.7 F=11.7 P<0.0001 P<0.0001 Mah=6.55 Biochar F=6.45 P<0.0001 134 135 136 137 138 139 140 141 142 143 144 145 146 12 147 148 149 150 151 Table S8 152 Statistical significance of the independent variables in the general discriminant 153 analysis, with fertilization treatment as the dependent categorical grouping variable 154 for the late paddy crop. Variable Value F P Salinity 0.864 8.77 <0.0001 Temperature 0.986 0.796 0.50 Water content 0.458 65.8 <0.0001 pH 0.258 160.1 <0.0001 CO2 emission 0.961 2.27 0.082 CH4 emission 0.943 3.37 0.020 N2O emission 0.969 1.81 0.15 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 13 171 172 173 174 175 Table S9 176 Statistical significance of the independent variables in the general discriminant 177 analysis, with fertilization treatment as the dependent categorical grouping variable 178 for the early paddy crop. Variable Wilks’ Lambda F P Salinity 0.706 15.3 <0.0001 Temperature 0.958 2.15 0.096 Water content 0.273 130 <0.0001 pH 0.429 64.8 <0.0001 CO2 emission 0.985 0.753 0.522 CH4 emission 0.943 2.95 0.035 N2O emission 0.996 0.199 0.897 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 14 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 Fig. S1 The locations of the study area and sampling sites (▲) in Fujian Province, 212 southeastern China. 213 214 215 216 217 218 219 220 221 222 223 224 225 15 226 227 Fig. S2. Temporal variation of air temperature and rainfall in the study area. 228 16