The present and future greenhouse gas budget of bioenergy crops in the UK

Lead Research Organisation: NERC Centre for Ecology and Hydrology
Department Name: Billett


Bioenergy is a key component of the UK Government's plans for tackling climate change. One of the major causes of increased atmospheric CO2 levels is the burning of fossil fuels releasing carbon that has been stored for centuries back into the atmosphere. In order to cut our use of fossil fuels we can grow crops for energy. Bioenergy (or 'biomass') crops are 'carbon neutral'; when burned to generate electricity they only release the same amount of CO2 back into the atmosphere as they fixed. Thus no 'extra' CO2 is released into the atmosphere. Miscanthus and short rotation coppice (SRC) willow are the dominant bioenergy crops grown in the UK. They differ from more traditional current arable crops in terms of their physiology, nutrient requirements and management. The impact of such differences on biogeochemical cycling and soil microbiology, particularly in relation to the production and oxidation of the greenhouse gases nitrous oxide (N2O) and methane (CH4), is unknown. It is essential to determine this in order to underpin future management of bioenergy cropping systems and to accurately project future greenhouse gas inventories. In this project we will measure emissions of CO2, CH4 and N2O from Miscanthus and SRC willow, and compare these to emissions from adjacently growing conventional crops. We will further investigate the processes producing N2O and quantify CH4 oxidation rates using stable isotope techniques under a range of controlled environment and managment conditions, and using molecular techniques will link these emissions to any differences or changes in the microbial population responsible. This information will be used to develop the JULES community model of CEH, parameterising water, energy, carbon and greenhouse gas balances for these bioenergy crops, and to simulate greenhouse gas emissions for UK land if converted to growing Miscanthus and SRC willow under present and future climates.
Description We have compared nitrous oxide , methane and carbon dioxide emissions from soils from bioenergy crops (elephant grass and willow) with agricultural food crops (wheat and oilseed rape). Because bioenergy crops recieve lower rates of nitrogen fertilisers, they emit less nitrous oxide. But they are NOT carbon neutral crops, and we need to know how much they emit to infomr those that want to sell and use bioenergy crops as low carbon replacements
Exploitation Route 1) The data are important for policy makers at national, EU and global levels: bioengery crops do have a carbon footprint too, and there are not enough data to quantify these at a national/global scale
2) Our work provided further research through the ETI funded 'ELUM project', the 'Ecosystem LandUse Modelling' project, which investigated the Soil Carbon and Greenhouse Gas emisisons from landuse change to bioenergy crops .
3) Due this NERC project we established links with INRA and worked together on the greenhouse gas fluxes from bioenergy, resulting in 2 publications ( doi:10.1016/j.biombioe.2014.07.003, DOI: 10.1111/gcbb.12223)
3) as a result of this project Ute Skiba was invited to the International Workshop 'Greenhouse Gas Emission from Oilseed Rape Cropping and Mitigation Options'
Venue: Thünen Institute, building 203, Bundesallee 50, Braunschweig to present the work of this project.
4) Our research and publications have led to European collaboration in the DON et al paper:'Land-use change to bioenergy production in Europe: implications for the greenhouse gas balance and soil carbon'. According to Web of Science®, our paper is one of 2015's 15 most-cited articles in Global Change Biology- Bioenergy.
5) Ute Skiba was invited to co-convene a Bioenergy session at the 2016 EGU meeting 'Climate impact of land management and competition between food and energy crops'
Sectors Agriculture, Food and Drink,Environment