Overview

One of the major scientific and societal challenges of our time is to secure the food supply for a growing population in a changing world. However, the productivity of crops is highly sensitivity to climate variations in temperature or rainfall and it is estimated that 30% globally (regionally up to 60%) of the observed variations in crop productivity can be explained by variations in climatic conditions. 

Agriculture itself is also a significant contributor to the emission of climate-relevant greenhouse gases. Globally, agriculture is the second largest emission source behind the energy sector. Agriculture contributes about 10% to the total greenhouse gas emissions of the UK (>40% for methane and >70% for N2O). Plants also emit biogenic volatile organic compounds (BVOC) such as methanol or isoprene which lead to aerosol formation and interact with atmospheric chemistry and thus affect climate and local air quality. 

If we want to move forward towards resilient and sustainable agriculture, it is important to understand how climatic fluctuations and change will impact agricultural crop production, what controls agriculture emissions of climate gases and how well we can project agricultural productivity and the related emissions into the future.

In this project, we will use detailed observations of key parameters characterising the meteorological conditions, soil conditions, crop productivity and trace gas fluxes of a monitored agriculture field used for crop production to evaluate the fundamental interplay between productivity, trace gases fluxes and external (meteorological) drivers. This will then be used to test our current understanding of plant functioning as represented by state-of-the-art land surface models, which form a key element in climate and Earth System models used for forecasting our future climate and the implication of climate change on regional ecosystems and agriculture.

The goals of this project are detailed observations of trace gas fluxes of a site similar to extensive crop prodcution and establishing links between climatic variations, trace gase fluxes and productivity. The project takes advantage of a well established collaboration of the Dept. of Geography  and G’s Fresh in East Anglia.

Soil trace gas flux system using automatic soil chambers. This allows to measure a large set of gases including CO2, CH4, CO and N2O using state of the art state analysers.

Methodology

The project will focus on simultanous measurements of trace gas fluxes from crops and soils under different cropping regimes using flux chambers and Eddy Covariance measurements. In addition to the CO2 and H2O fluxes from the LiCOR 8100 system, simultanously fluxes of CO2, CH4, N2O, CO and 13C in CO2 will be measureed with an Ecotech in-situ FTS trace gas analyzer using the flux gradient method. Fluxes from BVOCs will be obtained with a PTR-TOFMS (proton transfer reaction-time of flight- mass spectrometer). Complemented with meteorological measurements and information on the field site, these datasets will detailed evaluations of trace gas fluxes, their variations and underlying drivers. We will use the state-of-the-art UK land surface model JULES, which includes a realistic description of the carbon, water, energy cycles,  to assess the links between climatic variations, trace fluxes and productivity and to draw conclusions on the implications of future climate change.

Training and Skills

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. 

The student will acquire key skills and expertise in field work and flux measurements, an in-depth understanding of the carbon cycle and in land surface modelling. The student will also obtain a range of transferable skills ranging from data visualization and data analysis to presentation skills and working in a cross-discipline environment. The student will conduct a visit to the partner from University of Bremen who will provide specific training for the in-situ FTS instrument. The student will also participate in a national or international summer school with a focus on carbon cycle and flux measurements (e.g. from ICOS).  

 

Timeline

Year 1:  Setup and training of the in-situ FTS instrument for flux observations. Evaluation of the greenhouse flux measurements. Visit to University of Bremen. 

Year 2: Addition of the BVOC fluxes measurements. Statistical analysis of meteorological data, soil data, productivity and trace gas fluxes. Attendance of a Summer school with a focus on greenhouse gases and fluxes (eg ICOS summers school).  

Year 3: Evaluation of model calcualtions from the JULES land surface model against observations from the field site. Presentation of the results at a major European conference (EGU conference).

Partners and collaboration (including CASE)

The supervisory team will consist of:

Prof. Hartmut Boesch, Head of Earth Observation Science, Department of Physics and Astronomy and divisional director for National Centre for Earth Observation.

Dr. Joerg Kaduk, Associate Professor, Department of Geography.

Prof. Paul Monks, Professor of atmospheric chemistry.

A partner for this project will Dr. Thorsten Warneke, University of Bremen who is an expert in in-situ FTS measurements.

The agricultural partner, G’s fresh, is one of the largest vegetable growers in the UK. There is potential to develop this into a CASE studentship.

Further Details

It is strongly advised that you contact the supervisor Prof. Hartmut Boesch (Hartmut.boesch@le.ac.uk) before applying