lewis peake phd project school of environmental sciences university of east anglia norwich, uk...

Lewis PeakeLewis PeakePhD project PhD project

School of Environmental SciencesSchool of Environmental Sciences

University of East AngliaUniversity of East Anglia

Norwich, UKNorwich, UK

Supervisor: Dr Brian ReidSupervisor: Dr Brian Reid

Soil Science in a Changing World, Wageningen, Sept 18-22, 2011

• Essentially a type of charcoal, but two distinctions:

– Created by thermal decomposition of biomass with little or no oxygen (pyrolysis or gasification)

– Intended as a soil amendment and a means of storing carbon

• Scientific study of biochar is about ten years old

• Terra preta de índio (Indian black earth)

Biochar amendment to improve soil properties and sequester carbon Lewis Peake 2

What is biocharWhat is biochar

• Global soil reserves represent a large potential carbon sink BUT... traditional manures break down and oxidize rapidly

• Contains C in a form which is highly resistant to degradation

• Potential to sequester large amounts of C in the soil with a residence time of hundreds and possibly thousands of years

• Potential to be a C negative form of geo-engineering

• Research suggests that biochar use has many other soil benefits: chemical, physical and biological


Why is biochar important?Why is biochar important?

• Sequesters carbon in the soil

• Improves soil productivity, especially on poor soils

• Improves water retention / reduces water demand

• Improves water quality / less downstream pollution

• Reduces emissions of greenhouse gases from the soil

• Increases microbial activity

• Biofuel as a by-product and a renewable means of sustaining further biochar production


The apparent benefits of BiocharThe apparent benefits of Biochar

• If biochar is a viable means of boosting crop yields:

– What specific changes occur? – What rates of application are appropriate?

– Do different types of soil respond in different ways? – If, e.g. sand and clay soils respond in different ways, how would

a transitional soil type behave – a loam or a silt or a sandy clay?


The research questionThe research question

• To compare the physical and chemical responses to biochar of four contrasting agricultural soil types

• To use one type of biochar at a range of doses

• Laboratory experiment to test physical and hydrological effects, e.g. AWC

• 2-year outdoor pot trial to test mainly chemical effects

• 2-year farm trial to test range of effects

• Ultimate aim: strategic advice on biochar application


The approachThe approach

• Some research evidence of sand/ clay differing responses to biochar + texture is stable property

1. Loamy sand: acid, low CEC excessively drained

2. Sandy loam: neutral pH, medium CEC, freely drained

3. Loam: neutral pH, med-high CEC, imperfectly drained

4. Silty clay loam: calcareous, high CEC, estuarine,

poorly drained


Soil type selectionSoil type selection

• Ready supply on our “doorstep”:– UEA Combined Heat & Power biomass plant– Uniform feedstock of softwood sawmill waste – Gasification at 800 o C– Output 300 t/yr biochar

• Project limited to one type of biochar– Feedstock & production temperature important BUT...– Different types of biochar beyond scope– Project includes n soils / doses / replicates– Impossible to study multiple biochars as well


Biochar selectionBiochar selection

• Physical & hydrological testing with winter wheat

• Tested 5 soils for:

– Field Capacity– Bulk Density– Available Water Capacity

• Biochar doses: 0/0.1/0.5/2.5 % (≈ 0/4/20/100 t ha-1)


Laboratory experimentLaboratory experiment


Results: Soil Moisture @ Field CapacityResults: Soil Moisture @ Field Capacity


Results: Bulk DensityResults: Bulk Density


Results: AWC by weightResults: AWC by weight


Results: AWC by volumeResults: AWC by volume

• Mainly chemical testing with winter wheat

• Quarterly sampling over two years

• Biochar doses: 0/0.1/0.5/2.5 % (≈ 0/4/20/100 t ha-1)

• 4 soils x 4 treatments x 4 replicates = 64 pots

• Comprehensive analysis: cations, anions, pH, CEC

• Collaborating with U/G project on one soil type:– Includes fertilized treatments

– Analyses includes CO2 emissions


Outdoor pot trialOutdoor pot trial

• Local farm estate which includes the 4 core soils

• 3 of these soils are naturally low in organic matter:– Aggravates drought risk which climate change has increased– Structural problems– Erosion risk– Buyers discouraging use of organic manures

• Scaled-up version of lab and pot trials:– 3 soils to receive single dose; one to have 4 doses– Emphasis will be on physical & hydrological properties– Soil moisture release curves using Tempe cell cores


Long-term farm trialLong-term farm trial

• Global Food Security:– Increased yields; Reduced erosion risk

• Water Resources:– Enhanced water retention; Improved water quality

• Biodiversity:– Enhanced microbial activity; Reduced downstream pollution

• Governance & Policy:– Strategic geo-engineering; C credits opportunity

• Climate Change:– Carbon sequestered; N2O & CH4 emissions suppressed;

– Part of a sustainable biomass/biofuel system


Biochar – a solution in a changing world?Biochar – a solution in a changing world?

lewis peake phd project school of environmental sciences university of east anglia norwich, uk...

Documents

soil properties

soil amendment

biochar use

drained biochar amendment

biochar important

emissions biochar amendment

biochar selection slide

biological biochar amendment