electronic supplementary material
soils, sec 3 • remediation and management of contaminated or degraded lands • research article
Biochar effects on soil water infiltration and erosion under seal formation conditions: rainfall simulation experiment
Vikas Abrol1,2 • Meni Ben-Hur1 • Frank G. A. Verheijen3 • Jacob J. Keizer3 • Martinho A. S. Martins3 • Haim Tenaw1 • Ludmilla Tchehansky1 • Ellen R Graber1
Received: 13 December 2015 / Accepted: 10 May 2016
© Springer-Verlag Berlin Heidelberg 2016
Responsible editor: Yong Sik Ok
1 Institute of Soil, Water and Environmental Sciences, TheVolcani Center, ARO, Bet Dagan, Israel
2 Advance Centre for Rainfed Agriculture, Sher-e-Kashmir University of Agricultural Sciences & Technology, Kashmir
3 Centre for Environmental and Marine Studies, Department of Environment and Planning, University of Aveiro, Portugal
Ellen R Graber
ANOVA results of the statistical models are given below.
Model 1.Calcareous loam. A single rainstorm was carried out in 4 replicate blocks, where each block had two trays with different biochar levels (0 or 2%). The one-way ANOVA with block model was used to evaluate the effect of the independent variable ‘biochar level’ on the dependent variables‘FIR’and ‘soil loss’.
Table ESM-1: FIR (Final infiltration rate) for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.4226
Block & Random / 3 / 0.5859
Table ESM-2: Soil Loss for the calcareous loam
Source / DF / Prob > FBiochar / 1 / 0.0595
Block & Random / 3 / 0.9682
Model 2: Calcareous loam. Leachate during the storm was collected in four fractions and analyzed for EC, Ca, Mg, Na contents; SAR was computed. A two-way repeated measures ANOVA with block model was used to examine the effect of the independent variables ‘biochar level’ (0 or 2%) and ‘fraction’ (4 volume fractions), and the interaction between them on the dependent variables ‘EC’, ‘Ca’, ‘Mg’, ‘Na’, ‘SAR’.
Table ESM-3: EC for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.0420
Fraction / 3 / <0.0001
Biochar*Fraction / 3 / 0.5162
Block & Random / 3 / 0.2880
Biochar*Block & Random / 3 / 0.0887
Table ESM-4: Na for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.6455
Fraction / 3 / 0.5855
Biochar*Fraction / 3 / 0.4506
Block & Random / 3 / 0.3259
Biochar*Block & Random / 3 / 0.0164
Table ESM-5: Ca for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.5658
Fraction / 3 / 0.8140
Biochar*Fraction / 3 / 0.6815
Block & Random / 3 / 0.5225
Biochar*Block & Random / 3 / 0.5506
Table ESM-6: Mg for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.6823
Fraction / 3 / 0.6180
Biochar*Fraction / 3 / 0.8043
Block & Random / 3 / 0.0265
Biochar*Block & Random / 3 / 0.5339
Table ESM-7: SAR for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.7227
Fraction / 3 / 0.2351
Biochar*Fraction / 3 / 0.3111
Block & Random / 3 / 0.3550
Biochar*Block & Random / 3 / 0.0059
Model 3: Calcareous loam at two levels of biochar (0 and 2%). A one-way ANOVA with block model was used to evaluate the effect of biochar level on soil bulk density following the rainstorm.
Table ESM-8: Soil Bulk Density for the calcareous loam
Source / DF / Prob > FBiochar level / 1 / 0.9447
Block / 3 / 0.7755
Model 4: Non-calcareous sandy loam soil. A first rainstorm was carried out in 4 blocks, each block with 5 trays having different concentration of biochar (0, 0.25, 0.5, 1, and 2% by weight). The one-way ANOVA with block model was used to evaluate the effect of the independent variable ‘biochar level’ on the dependent variables‘FIR’and ‘soil loss’.
Table ESM-9: FIR (Final infiltration rate)for the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / <0.0001
Block & Random / 3 / 0.7326
Table ESM-10: Post-hoc FIR means testing Tukey HSDfor the non-calcareous sandy loam soil
Biochar level / Means test / Least square mean2 / A / 19.61
1 / B / 13.73
0.5 / B / 13.03
0.25 / B / 11.88
0 / B / 11.31
Levels not connected by the same letter are significantly different at = 0.05
Table ESM-11: Soil Lossfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar / 4 / 0.0050
Block & Random / 3 / 0.0272
Model 5: Non-calcareous sandy loam soil. A second storm was carried out in four blocks at two levels of biochar (0 and 2%). A two-way repeated measures ANOVA with block model was used to compare ‘Soil loss’ and ‘FIR’ between the first and the second storms at two levels of biochar (0 and 2%).
Table ESM-12: FIR (Final infiltration rate) comparison of two rainstormsfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 1 / 0.0022
Rainstorm / 1 / 0.0065
Biochar*Rainstorm / 1 / 0.0820
Block & Random / 3 / 0.2968
Biochar*Block & Random / 3 / 0.3048
Table ESM-13: Soil Loss comparison of two rainstormsfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 1 / 0.0182
Rainstorm / 1 / 0.0411
Biochar*Rainstorm / 1 / 0.5271
Block & Random / 3 / 0.4295
Biochar*Block & Random / 3 / 0.2955
Model 6: Non-calcareous sandy loam soil. Leachate during the first storm was collected in four fractions and analyzed for EC, Ca, Mg, Na contents; SAR was computed. A two-way repeated measures ANOVA with block model was applied to examine the effect of the independent variables ‘biochar level’ and ‘fraction’ and the interaction between them on the dependent variables ‘EC’, ‘Ca’, ‘Mg’, ‘Na’, ‘SAR’. In order to meet the model assumptions, Ca concentrations were log transformed, and Mg concentrations and SAR values were transformed by inverse square root.
Table ESM-14: ECfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / 0.1387
Fraction / 3 / <0.0001
Biochar*Fraction / 12 / <0.0001
Block & Random / 3 / 0.2135
Biochar*Block & Random / 12 / 0.0013
Table ESM-15: Cafor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / <0.0001
Fraction / 3 / <0.0001
Biochar*Fraction / 12 / 0.0002
Block & Random / 3 / 0.0530
Biochar*Block & Random / 12 / 0.0007
Table ESM-16:Mgfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / 0.0145
Fraction / 3 / <0.0001
Biochar*Fraction / 12 / 0.0087
Block & Random / 3 / 0.7307
Biochar*Block & Random / 12 / <0.0001
Table ESM-17:Nafor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / 0.0155
Fraction / 3 / <0.0001
Biochar*Fraction / 12 / <0.0001
Block & Random / 3 / 0.4295
Biochar*Block & Random / 12 / <0.0001
Table ESM-18:SARfor the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 4 / <0.0001
Fraction / 3 / 0.0001
Biochar*Fraction / 12 / <0.0001
Block & Random / 3 / 0.3066
Biochar*Block & Random / 12 / <0.0001
Table ESM-19: Tukey results for 1st rainstorm in non-calcareous loamy sand
Fraction / Biochar level / EC / Ca / Mg / Na / SARI / 0 / B / B / A / B / B
0.25 / AB / B / BC / B / AB
0.5 / AB / B / AB / B / A
1 / AB / B / AB / B / A
2 / A / A / C / A / A
II / 0 / A / C / A / A / B
0.25 / A / B / B / AB / B
0.5 / A / BC / AB / AB / B
1 / A / C / AB / AB / B
2 / A / A / AB / B / A
III / 0 / A / C / A / A / C
0.25 / A / B / B / B / BC
0.5 / A / C / A / BC / B
1 / A / C / A / BC / B
2 / A / A / AB / C / A
IV / 0 / A / BC / A / A / C
0.25 / A / B / A / AB / BC
0.5 / A / BC / A / B / BC
1 / A / C / A / B / B
2 / A / A / A / B / A
Model 7. Non-calcareous sandy loam soil compared with calcareous loam at two levels of biochar (0 and 2%): A two-way repeated measures ANOVA with block model was used to examine the effect of the independent variables ‘soil type’ and ‘biochar level’ on the dependent variables ‘FIR’ and ‘soil loss’.
Table ESM-20: FIR compared between the calcareous loam and the non-calcareous sandy loam soil
Source / DF / Prob > FSoil type / 1 / <0.0001
Biochar level / 1 / 0.0014
Soil type*Biochar level / 1 / 0.0007
Block(Soil type) & Random / 6 / 0.6014
Table ESM-21: Soil loss compared between the calcareous loam and the non-calcareous sandy loam soil
Source / DF / Prob > FSoil type / 1 / <0.0001
Biochar level / 1 / 0.0056
Soil type*Biochar level / 1 / 0.3999
Block(Soil type) & Random / 6 / 0.9083
Model 8: Non-calcareous sandy loam soil: A one-way ANOVA with block model was used to evaluate the effect of biochar level (0 or 2%) on soil bulk density following the 2nd storm.
Table ESM-22: Soil Bulk Density for the non-calcareous sandy loam soil
Source / DF / Prob > FBiochar level / 1 / 0.0349
Block / 3 / 0.5974