Biological and Environmental Engineering

Soil & Water Research Group

Effects of Biochar and Charcoal on Soil-Hydraulic Properties

Haimanote K. Bayabil1*, Johannes C. Lehmann2, Birru Yitaferu3, Cathelijne

Stoof1, and Tammo S. Steenhuis1

1 Department of Biological and Environmental Engineering, Cornell University, Ithaca NY 14850, USA.

2Department of Crop and Soil Science, Cornell University, Ithaca NY 1850, USA. 3 Soil and Water Research

Directorate, Amhara Region Agricultural Research Institute, Bahir Dar, Ethiopia

Nile Basin Development Challenge (NBDC) Science WorkshopAddis Ababa, Ethiopia, 9–10 July 2013

Biological and Environmental Engineering

Soil & Water Research Group

Introduction

Agri. Productivity

• Scarce and expensive

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Soil & Water Research Group

Biochar-Charcoal Amendments

Soil

Physic

al

Hydraulic

Chemical

Soil

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Soil & Water Research Group

Impacts on Soil Moisture

Coarse

CLAY

SAND

Soil Moisture

Fine

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Soil & Water Research Group

Objectives

1. To assess dominant soil physical & hydraulic properties in the watershed

2. To evaluate the effects of biochar and charcoal amendments on permeability and moisture retention characteristics of drying soils.

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Soil & Water Research Group

Study Site Location:10o40' N/37o31’E Area is 113.4 ha Elevation:2407–2507m

Data Sources 1. Field Measurements

Infiltration, Soil depth

2. Laboratory tests

Texture, BD, OC, & pH

3. Column Experiments

54 soil-cores (30 cm length and 12 cm height)

Two Biochar and Three Charcoal treatments @ 5g/kg soil

4. Five year event precipitation data (1989-1993)

Methodology

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Field Soil Properties

Results & Discussion

Clay=42%OC =1.1%

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Soil & Water Research Group

Precipitation & Infiltration Rate

21%

<15min & 6.3mm/h = 68%

Av. Precipitation = 1616mm/yr fs => 1.9-36.4mm/h

(CV= 70%)

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Waterlogging Issues

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Treatments Effect on Soil Moisture Retention

Columns with diff letters are sign at (p<0.05).

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Treatments Effect Available Water Content (AWC)

* Treatment differences were not significant (p>0.05)

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Soil & Water Research Group

Treatments Effect on Hydraulic Conductivity (Kr)

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Possible Mechanisms ?? Macropore formation

Clay Flocculation  

*pHCa2+ Mg2+ K+ Na+

MCAR SAR 

(CmolC/Kg)

Biochar            Corn 9.4 36.59 66.93 65.92 4.83 31.10 2.13Oak 7.5 5.12 0.21 4.27 1.00 10.20 1.93

Charcoal            Acacia 8.2 0.08 0.10 0.15 0.01 1.77 0.13

Eucalyp 8.7 0.07 0.01 0.13 0.03 2.47 0.40

Hydrophobicity

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Soil & Water Research Group

Conclusion

1. Biochar and Charcoal improve hydraulic property (permeability) of degraded soils with waterlogging issues

2. Considering soil physical & hydraulic properties is crucial for effective soil & water management planning.

Biological and Environmental Engineering

Soil & Water Research Group

Ongoing Research

Funding ─Norman Borlaug International Science & Technology Fellowship (LEAP)─Higher Education for Development (HED)

GHGRunoff & Erosion