Effect of Wood Biochar Amendment to Sand on Leachate Water Quality

with Repeated Dairy Manure Application: A Soil Column Study

Alysa BradleyUW-Madison, WI

April 2, 2015

Presentation Outline Introduction

Experimental Design

Leachate Results

Retention Results

Conclusions

Limitations and Recommendations for Future Work

Introduction

Introduction

Biochar - a carbon-rich substance produced as a co-product by the thermal degradation of organic matter under a limited supply of oxygen.

Experimental Design: Biochar

• Hybrid poplar chips

• Slow pyrolysis at 450°C

• Applied at rates of 1, 2 and 5 % by weight.

Experimental Design: Soil columns

5% 2% 1% 0% C

Experimental Design: Leaching – Volume

– pH

– Biological Oxygen Demand (BOD5)

– Nitrite (NO2)

– Nitrate+Nitrite (NO3+NO2)

– Total Phosphorous (TP)

– Total Nitrogen (TN)

– Total Kjeldahl Nitrogen

– Ammonia

5% 2% 1% 0% C

Leachate Results: pH

Leachate Results: BOD5

Leachate Results: Cumulative TN

Leachate Results: Cumulative NO3

Leachate Results: NO3

Concentration

Leachate Results: Cumulative Ammonia

Leachate Results: Cumulative TP

Nutrient Retention Results: N

Nutrient Retention Results: TP

ConclusionsHybrid poplar biochar in sand:

• Increased leachate pH

• Decreased leachate BOD5

• Decreased leachate nitrogen

• Some increased TP in leachate

Limitations and Recommendations• Limitations• Simulated precipitation• Relatively constant temperature• No plantings• No measured soil emissions

• Recommendations• N cycling and mechanisms for change• Effect on emissions and crop yields• Field trials• Alternative application strategies

Questions?