1. Long term Biochar versus Wood Ash Agronomic Field Trial at 6 months
Dr Eleanor Swain, Prof Davey Jones, Prof Dave Chadwick, Dr Paul Hill
25th March 2015

2. Long term Biochar versus Wood Ash Agronomic Field Trial
Experimental Aims:
Directly compare the agronomic value of BC versus WA when used in grassland management
Evaluate the impact of BC and WA on soil quality at the field scale over multiple seasons
The trial was set up to evaluate whether the product of wood pyrolysis (i.e. biochar) was better than the product of incineration (i.e. wood ash) when used in grassland management (for sheep grazing and silage production).
We are studying various aspects of soil and plant quality within this trial including forage growth and yield, soil biodiversity, greenhouse gas emissions, soil nutrient effects, nitrogen and carbon dynamics, water dynamics etc. 

3. Biochar Organic material burned in the absence of O2
Bi-product of bioenergy
Carbon sequestration in soil using biochar
Potential secondary agronomic benefits

4. Wood ash Residue remaining after the combustion of wood
Acts as a liming agent
Neutralizes soil acidity
Reduces Al toxicity
Potential secondary agronomic benefits
source of Ca, K, Mg and P
provide a significant source of nutrients; Ca, K, Mg and P (Someshwar 1996, Kuba et al., 2008),
raising the theory that ash could be utilised as a fertilizer (Kuba et al., 2008).

5. Long term Biochar versus Wood Ash Agronomic Field Trial
Experimental Set-Up:
Randomised block design field trial
Biochar was added at 10 t ha-1 in 2014
Wood ash was added at a rate equivalent to t ha-1 of biochar which equated to 0.57 t ha-1 (i.e. ash content of biochar ca. 5.7%)
Mixed hardwood biochar powder to maximise its surface area (the old trial used large biochar chips).
The wood ash was created from the biochar so that they were directly comparable.

6. Long term Biochar versus Wood Ash Agronomic Field Trial
Experimental Set-Up:
Randomised block design field trial
Biochar was added at 10 t ha-1 in 2014
Wood ash was added at a rate equivalent to t ha-1 of biochar which equated to 0.57 t ha-1 (i.e. ash content of biochar ca. 5.7%)
Mixed hardwood biochar powder to maximise its surface area (the old trial used large biochar chips).
The wood ash was created from the biochar so that they were directly comparable.
Mixed hardwood BC powder

7. Long term Biochar versus Wood Ash Agronomic Field Trial
Experimental Set-Up:
Randomised block design field trial
Biochar was added at 10 t ha-1 in 2014
Wood ash was added at a rate equivalent to t ha-1 of biochar which equated to 0.57 t ha-1 (i.e. ash content of biochar ca. 5.7%)
Mixed hardwood biochar powder to maximise its surface area (the old trial used large biochar chips).
The wood ash was created from the biochar so that they were directly comparable.
Wood ash created from the combustion of biochar

8. Biochar & Wood ash Long term Trial with long term CO2 flux chambers at Henfaes Farm, Bangor University (18/09/14)

9. Biochar & Wood ash Long term Trial with long term CO2 flux chambers at Henfaes Farm, Bangor University (07/10/14)

10. Biochar & Wood ash Long term Trial with long term CO2 flux chambers at Henfaes Farm, Bangor University (10/03/15)

11. Soil Quality: soil moisture

12. Soil Quality: pH

13. Soil Quality: SOM, C & N

14. Soil Quality: soil nutrients

15. Soil Quality: soil nutrients

16. Soil Quality: PLFA Analysis
Microbial community biomass & structure
Using the whole PLFA pattern
have there been changes in the community due to a specific treatment?
Using specific PLFAs as markers to specific groups
have treatments had an effect on specific groups of microorganisms?

17. Agronomic Value: Grass 1st Cut (Nov 2014)

18. Preliminary Conclusions: 0-6 months
Relative to the Control:
BIOCHAR
↑ SM 2%
↑ SOM 1.8%
↑ pH 0.4 units
↑ NO3-N 55%
↑ C & N in grass
Relative to the Control:
WOOD ASH
↑ pH 0.25 units
↑ NO3-N 40%
↑ P in grass
↓microbial biomass

19. Future Work: 6-12 months Continue to monitor soil quality properties
Measure crop parameters
Evaluate long term CO2 emissions

20. Acknowledgements Any Questions?
Prof. Davey Jones
Prof. Dave Chadwick
Dr. Paul Hill
Lab Technicians: Sarah Chesworth & Gordon Turner
Field Technicians: John Evans & Alex King
Henfaes Staff: Llinos Hughes & Mark Hughes
Any Questions?

21. Lab Work
Soil priming
Sorption
Microbial biomass C & N