Biochar for crop growth and soil biodiversity

Melanie BennetUniversity of East Anglia

m.bennet@uea.ac.uk

The gasification + combined heat and power generator at the University of

East Anglia

What is biochar?

Many micro-pores = large surface areaGood microbial habitat

Stable and inert in soilResists microbial decompositionRetains nutrients

Biochar benefits •Carbon mitigation/sequestration•Reduced GHG emissions•Geo-engineering tool (?)

•Better soil for crops•Better crop productivity•Higher fertiliser use efficiency•Conservation benefits (biodiversity)•Renewable energy

-CHP -Pyrolysis + gasification•Drawbacks (crops for energy prod.)

•Feedstock from waste•Livestock feed additive•Improves soil conditions•Land remediation• Invasive species

!!HOT TOPIC!!!Biochar will

save the planet?

Leached nutrients are harmful

phot

osyn

thes

is Respiration

CO2

Net atmospheric C withdrawal = 0%

phot

osyn

thes

is

CO2

pyrolysis25%

25%

Respiration

Carb

on re

leas

e 50

%

Carb

on re

leas

e 5%

Bioenergy: Carbon neutral(reduces emissions from fossil furls)

25%

Net carbon withdrawal from atmosphere: 20%

…with biocharThe Carbon Cycle

The On-Farm Carbon Cycle

CO 2CO2

C

Biomass CCO + HSyngas

Organisms present at the root-soil interface affect the flux of nutrients in the soil (C-N-GHGs)

Soil organisms help particle aggregation in soil (exudates)

Provide food for higher predators

Improve plant disease resistance via competitive interactions

Amino Acids

Higher plants

Higher animals

Amino Acids

Nitrifying bacteria(Nitrobacter)

Nitrifying bacteria(Nitrosomonas)

Ammonia, urea

Nitrite

Nitrogen fixing bacteria

Atmospheric nitrogen

Bacterial function in soil

A gram of soil can contain approx.

1,000,000,000 fungi40,000,000,000 bacteria

Most microbial cells are inactive at any one time

Some cells can cause diseases such as tetanus

Many are very important for healthy soil ecosystem functioning

3 µ

m

Cytoplasm

DNA

Flagellum

Ribosome

Plasmid

Peptidoglycan

Cell wall

Bacterial form and function in soil

Microbial rhizophere community analysis

Microbial rhizophere community analysis

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