Soil carbon tipping points for pesticide regulation (REIDUENV17EE)

Background
Globally, soils store three times more carbon than the atmosphere. Two-thirds of this carbon is in the form of organic matter. Agricultural practices exert great pressures on soil organic matter; and, together with changes to climate, these are driving a decline in Soil Organic Carbon (SOC) status. In the coming decades agricultural intensification, to meet global food supply demands, will exert ever greater pressures on soil carbon.

Aims
This research seeks to expose the ‘tipping point’ at which SOC decline results in the loss of soils’ ability to attenuate and degrade pesticides. Impairment to a soil’s ability to attenuate and degrade pesticides has significant consequences for soil and water quality and the delivery of wider soil ecosystem services.

Approach and training
To deliver this research you will manipulate SOC levels and then make practical assessment of perturbations to soil physical and chemical attributes and its microbiology. You will gain practical experience in the assessment of key physical and chemical attributes of soil (e.g. texture, soil bulk density, soil penetration, water holding capacity, soil aggregate stability, SOC, total and major and trace elements and cation exchange capacity).
You will then link these assessments to changes observed in the fate and behaviour of pesticides in laboratory microcosm experiments and in the field. To achieve this you will learn, and apply, techniques to:
i) extract and quantify pesticide residues and their bioavailability,
ii) isolate and characterise (16S/18S rRNA gene sequencing) soil microbes involved in the degradation of pesticides, and
iii) monitor pesticide degradation using use 14C-radiotracers.

This project provides an excellent training opportunity to master techniques for the description of soil, the study of pesticide fate and behaviour and to evaluate microbial soil communities and their functioning.
These practical skills are highly transferable to the study of soil science, organic compounds in the environment and microbial adaptation to stress.
This project will be well suited to applicants with degrees that have a strong laboratory element e.g. BSc/MSc degrees in: Chemistry; Biochemistry; Microbiology; Environmental Sciences; Soil Science.