Understanding processes determining soil carbon balances under perennial bioenergy crops CARBO-BIOCROP

Lead Research Organisation: University of Southampton
Department Name: Centre for Biological Sciences

Abstract

In contrast to annual food crops, evidence suggests that biofuels from perennial bioenergy crops have a positive greenhouse gas (GHG) mitigation potential. However, the magnitude of this benefit has been recently questioned, since long-term and indirect effects may considerably reduce any GHG savings generated by the cropping system. Indeed, impacts on soil C have been identified as the weak link in life-cycle analysis of net carbon-equivalent benefit presented by bioenergy. Changes in rates of nitrous oxide (N2O) and methane (CH4) emission are relevant too since they have a large GHG warming potential, but these changes are mostly unquantified for perennial bioenergy cropping systems. Although several soil carbon and trace-gas models have been developed for agricultural and conventional forest systems these have not been parameterized and validated for transition of land-use to perennial bioenergy crops. To predict the changes in SOC that will occur one to three decades after establishing biomass crops, we need to establish (a) differences in turnover dynamics and fluxes of carbon under key biomass crops in terms of amount, quality and placement of carbon into the soil from the plant, and (b) mechanisms to overcome short-term loss of pre-existing soil carbon during transition (c) quantitative, process-based modeling approaches that are predictive, to explore future scenarios for optimum soil carbon management. The overarching aim of this project is to provide improved understanding of fundamental soil processes resulting in changes of soil carbon stocks and pools as a result of land conversion from arable/grassland to land-based renewables. The project focuses on impacts of land use change specifically to perennial bioenergy crops (fast growing SRC trees and grasses) where there is currently a significant knowledge gap. This project will generate new evidence to improve current understanding on how soil carbon processes, sequestration and emission, are affected by the introduction of perennial energy crops. The soil carbon balance is key to informing the debate on whether using these crops for bioenergy and biofuels will result in significant carbon savings compared to land use for food crops and the use of fossil fuels for heat, power and liquid fuels. In the long-term (beyond the life of this project), this will enable dynamic, spatially explicit modeling of GHG (C equivalents, abbreviated here as C) mitigation potential of land-based bioenergy systems across different climates and soil types of the UK. We wish to develop 'Carbon Opportunity Maps' for the UK. The work of the project will be undertaken in three workpackages dealing with data synthesis (WP1), experimental data collection (WP2) and modeling (WP3). Throughout the project we will use leverage of other resources including two flagship sites at Brattleby and Aberystwyth, where commercial-scale plantations are established and where several long-term measuring and monitoring activities are underway funded from elsewhere. Similarly, the modeling resources from within the project are extensive and funded from other sources that will be levered against the work here. They included DNDC, JULES, ROTH C and on-going modeling approaches for miscanthus and SRC. Outputs will include a new database of synthesized data for soil carbon under bioenergy crops. We will have tested and calibrated process-based models that are capable of simulating the dynamics of soil organic carbon, carbon sequestration and greenhouse gas emissions for perennial bioenergy crops in the UK. We will provide increased fundamental understanding of soil processes occurring under bioenergy cropping systems including the role of mycorrhizal associations and the effectiveness of biochar as a potential to optimize soil carbon and plant growth. We will develop capacity for future 'carbon opportunity' mapping.

Publications

10 25 50
 
Description Carbo-BioCrop has succeeded in providing important underpinning information of wide relevance to establish under what circumstances bioenergy cropping systems might be considered as 'sustainable'. In particular, the project focusses on the greenhouse gas balance of land us transitions to bioenergy. For example, we have compared what happens when arable land is converted to an energy crop such as miscanthus and what happens when grassland is converted to short rotation coppice willow.

Several different approaches were taken in the project and the outputs of the research are being widely used, both for further academic research and through impact to policy makers and commercial entities. One important approach was to use 'space for time' experiments where we compared soil carbon at side-by-side sites where bioenergy crops and other land-uses were in close proximity. This gives some indication of how soil carbon might change over time, for such transitions if many sites of different ages are compared. At the same time, we have quantified the mitigation potential for GHG balance of biochar application. This novel, high carbon substance has been suggested to have value in locking-up carbon in long-term soil sinks, as a geoengineering option. We have quantified the potential for this in UK bioenergy systems, in research led by Edinburgh University in research currently being considered for publication.

An important part of the soil that contributes to processes underpinning soil carbon fluxes is the microbial community and here we have used highly novel techniques to determine the impact on land use to change to bioenergy crops on the microbial fraction, as part of two PhDs at Warwick University.

We have also improved our process models underpinning maps on bioenergy yield and GHG balance and used a 'proof of concept' approach to analyse the consequences of land-use change for GHG balance in a spatial context in work at Southampton, UEA and Aberdeen, as an external partner. We are extending this analysis beyond that required by the grant to consider a wide range of ecosystems services.

Innovative field work has also been deployed over two season and at two sites to follow the short-term carbon signal from bioenergy crops to soil and gain or loss from the system using heavy 13C isotopic approaches. This has provided some of the first data on this aspect of carbon flow and we have elucidated important differences between behaviour in miscanthus and willow, in work led by CEH Lancaster.
Exploitation Route Most recently, the project data and outputs have been used in a publication by The Energy Technologies Institute

http://www.eti.co.uk/delivering-greenhouse-gas-emission-savings-through-uk-bioenergy-value-chains/

This report has synthesised the data from this and other projects to develop a blue-print for the UK to achieve significant carbon reductions in the UK energy system. The work from Carbo-BioCrop was key to this.


The project has quantified important effects of land-use change to second generation bioenergy crops on greenhouse gas balance. As such, these data are valuable to policy makers engaged in delivering the low carbon economy and a move away from fossil fuels. Understanding the whole life cycle carbon costs of bioenergy chains is controversial and the growing crop contributes considerably to this net cost. Understanding how land use change transitions impact on GHG balance will be important moving forward in this area.

Our data has provided underpinning input to the meta-model being developed by ETI, with a GUI and simplified data matrices enabling a wdie range of users to have access to this tool to test the impacts of differing land use change scenarios. Our underpinning data of value to this tool include 1. soil carbon validation data, 2. yield model validation and development of process-based models that describe the yield of several second generation non-food crops including willow, poplar and miscanthus and 3. Flux data of carbon flux at three contrasting land use change sites in Lincolnshire, Wales and Sussex.

In addition the project has contributed to the training of six PhD students, either wholly funded or partially supported by the grant. These PhD students took the initiative and have developed a new researcher network for early career researchers in the area of bioenergy crops. They now meet annually and present their research and engage in active discussions. We are currently negotiating for this groups to become part of the EPSRC SUPERGEN hub in Bioenergy.

Our research is also being taken forward by Phase III of UKERC, as part of the Energy pathways and Modelling workstreams and in the EPSRC Bioenergy Challenges I and II research consortium. in Challenge I, the GHG balance data will be supplied to the whole system modelling activity, to develop the Biomass Value Chain Model for the UK. In Bioenergy Challenge II - MAGLUE, this project will kick-off in January 2015 and takes forward much of the research from CBC. MAGLUE is concerned with Measurement and Analysis of GHGs in bioenergy systems and will extend CBC findings to include LCA approaches for the whole life cycle and will begin by considering several overseas feedstocks from Asia and northern USA. CBC data provide our starting point for this study and MAGLUE now provides funds to continue with the field sites for a further 3 years, obtaining long term monitoring data.
Sectors Agriculture

Food and Drink

Energy

Environment

Government

Democracy and Justice

URL http://www.carbobiocrop.ac.uk
 
Description The outputs from this research have been used in several modelling activities for UK Government Energy Policy development. In particular, we have contributed to UKTM Energy Systems model, ESME model, and Biomass Vlaue chain Model (BVCM) of ETI.
First Year Of Impact 2015
Sector Agriculture, Food and Drink,Energy,Environment,Government, Democracy and Justice
Impact Types Policy & public services

 
Description Appointed to Advisory Group, Committee on Climate Change, Bioenergy Review
Geographic Reach Multiple continents/international 
Policy Influence Type Membership of a guideline committee
URL https://www.theccc.org.uk/bioenergy-review-2018-call-evidence/
 
Description Bioenergy: Enabling UK biomass
Geographic Reach National 
Policy Influence Type Citation in other policy documents
Impact This high-level report was released by The Energy technologies Institute following our NERC -funded CBC project.
URL http://www.eti.co.uk/bioenergy-enabling-uk-biomass/
 
Description Biomass for UK energy
Geographic Reach National 
Policy Influence Type Participation in a guidance/advisory committee
URL https://researchbriefings.files.parliament.uk/documents/POST-PN-0690/POST-PN-0690.pdf
 
Description Delivering greenhouse gas emissions from UK bioenergy chains
Geographic Reach National 
Policy Influence Type Implementation circular/rapid advice/letter to e.g. Ministry of Health
URL http://www.eti.co.uk/delivering-greenhouse-gas-emission-savings-through-uk-bioenergy-value-chains/
 
Description Participation in BEIS consultation on the Bioeconomy
Geographic Reach National 
Policy Influence Type Contribution to a national consultation/review
 
Description The research on bioenergy has impacted Committee on Climate Change thinking on sustainable supply of UK bioenergy
Geographic Reach National 
Policy Influence Type Citation in other policy documents
Impact The Committee on Climate Change is an independent statutory body established under the Climate Change Act, 2008. It is there to advise Government on emissions targets and reports to Parliament on progress made to reduce greenhouse gas balance. In 2011CC wrote a specialised review on the role that bioenergy could play in contributing to GHG emissions reductions targets and research on biomass supply from the laboratory of G. Taylor is quotes in this review that informs Government Policy Development.
URL https://www.theccc.org.uk/archive/aws2/Bioenergy/1463%20CCC_Bioenergy%20review_bookmarked_1.pdf
 
Description Bioenergy Value Chains: Whole System Analysis and Optimisation
Amount £1,560,068 (GBP)
Funding ID EP/K036734/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 08/2013 
End 08/2017
 
Description Industrial Decarbonization Research and Innovation Center
Amount £19,903,412 (GBP)
Funding ID EP/V027050/1 
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 03/2021 
End 04/2024
 
Description MAGLUE - Measurement and Analysis of bioenergy greenhouse gases: integrating GHGs into LCAs and the UK bioenergy value chain modelling environment
Amount £1,100,000 (GBP)
Funding ID EP/M013200/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 03/2015 
End 02/2018
 
Description Rural Development Plan; Plan Torri Tir Newydd
Amount £295,284 (GBP)
Organisation Government of Wales 
Sector Public
Country United Kingdom
Start 11/2017 
End 11/2019
 
Description Sub-contractor to Imperial College of Science, Technology and Medicine, London in the EIT-funded project ADMIT-Bio-Succinnovate under the Climate-KIC programme 
Organisation Imperial College London
Country United Kingdom 
Sector Academic/University 
PI Contribution We supported the spatially specific estimates of biomass in different UK regions available for the bio-economy, here the resource for bio-renewable succinic acid. We trained and co-supervised the PhD student Yuanzhi Ni at Centre for Environmental Policy, Imperial College London, to calibrate, validate and upscale an existing process-based crop growth model. We agreed to carry out the following services for Imperial: 2.1. (a) those as set out in Schedule 1 annexed hereto which includes the provision of an interim report including yield, spatial carbon stocks maps and Land based GHG emission factors for feedstock supply locations (England, Wales, Hungary and France) to be delivered by end of November 2016. A conference paper and a peer-reviewed paper are published/under review, respectively.
Collaborator Contribution Partner at Imperial College (Dr Jeremy Woods, Centre for Environmental Policy) were leader of Work Package 8 in the Bio-Succinnovate project. We were initially a partner in our own right but changed to being a subcontractor (16122 -Consultancy agreement Rothamsted Biosuccinnovate). Imperial College administered and paid a reasonable fee (€15k).
Impact Conference paper at the International Bioenergy Conference and Exhibition, Shanghai: Assessing Availability and Environmental Impacts of Lignocellulosic BIOMASS Feedstock Supply - Case Study for a Catchment in England (9 pages) Ni, YZ, Mwabonje, O., Richter, G., Qi, A., Yeung, K, Patel, M. Woods, J. (2018) ASSESSING AVAILABILITY AND ENVIRONMENTAL IMPACTS OF LIGNOCELLULOSIC BIOMASS FEEDSTOCK SUPPLY - CASE STUDY FOR A CATCHMENT IN ENGLAND Biofpr (Accepted for publication; revisions to be submitted by 8 April 2018)
Start Year 2015
 
Description Article for NERC magazine, Planet Eart - Called to Account - bioenergy's carbon footprint 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact An article on the project was written for the NERC Planet Earth magazine that has extremely wide coverage. http://www.nerc.ac.uk/latest/publications/planetearth/archive/planet-earth-aut14/
Year(s) Of Engagement Activity 2014
URL http://www.nerc.ac.uk/latest/publications/planetearth/archive/planet-earth-aut14/
 
Description Attendance and presentation at the International Bioenergy Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Professor Gail Taylor Chaired and organised a session at this international conference. Two presentations were made from the project, one by Dr Zoe Harris on measurements of GHG balance and one by Dr Robert Holland on wider consideration of ecosystem services.
Year(s) Of Engagement Activity 2014
URL http://bioenergy2014.co.uk/
 
Description Bioenergy Presentation at the University of Brawijaya, Indoensia 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact A seminar series from CEH and an Indonesian Government Regional Planning Authority in Java. The purpose was to exchange knowledge and ideas around sustainable agriculture in SE Asia. The audience comprised University Staff, postgrad students and some members of government. An active collaboration is now on-going with the University of Brawijaya through NERC ODA Award NE/R000131/1. Part of the CEH lecture is now used by university lecturers.
Year(s) Of Engagement Activity 2017
 
Description Biomass and Energy Crops V Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact There were talks and discussion over two days and an open panel discussion and interviews on the second day, see link below
Year(s) Of Engagement Activity 2015
URL https://www.youtube.com/channel/UCZCMCCAkmtgV5TsNaBCpdIQ/videos
 
Description Providing evidence to Committee on Climate Change for the 2018 Bioenergy Review 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact R Holland (SOTON) discussed ongoing work with Jenny Hill from the Committee on Climate Change and the possibility of contributing to their bioenergy and land use reviews due to be published end of 2018
Year(s) Of Engagement Activity 2017,2018
URL https://www.theccc.org.uk/bioenergy-review-2018-call-evidence/
 
Description Visit to Drax and interaction with power generation industry 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact R Holland (SOTON) visited Drax powerstation together with Casper Donnison (Soton ADVENT PhD) and Astley Hastings (Aberdeen) and met sustainability team. Discussed ongoing work within UKERC relating to international implications of UK energy. Subsequent follow up meetings to discuss areas for joint research.
Year(s) Of Engagement Activity 2017