Sustainable Soil & Grassland Systems
My research interests are in mathematical modelling of agricultural systems and in using these models to identify ways in which we could develop more sustainable agricultural practices. Current projects include:
- Targets for sustainable and resilient agriculture (TSARA)
The UN Sustainable Development Goals (SDGs) set targets for a range of societal challenges that must be addressed simultaneously and across developing and developed countries alike. The Targets for Sustainable and Resilient Agriculture (TSARA) project aims to identify the role of agricultural systems in Europe and New Zealand in achieving the SDGs and to develop pathways to reaching these targets. My role in this project is to use mathematical models based on our understanding of biological and physical processes to quantify the trade-offs between different indicators (e.g. agricultural production and carbon emissions) and thus set acheiveable targets.
- Water-Energy-Food Webs (WEFWEBs)
This is a collaborative project across 8 UK institutions aiming to identify the dynamic, interlinked inter-dependencies across the nexus networks which are physical (water, waste, energy and food), social and political (individual, regulatory and policy), ecological and digital at multiple, nested scales (local, regional and national). My role is in translating the quantitative understanding embedded in models of agricultural production systems and ecosystem services into forms that can be used and analysed alongside data from other sources. I work in particular on a case study of the Tamar river catchment.
Past projects: The fundamental basis of biological soil resilience Quantifying and comparing the resilience of soil microbial communities after repeated drying and rewetting stresses. To do this, we have developed a model of that characterises the functional resilience of the soil biology in terms of a few model parameters which are fitted to high resolution respiration data collected after a rewetting event using soils collected from across England and Wales. We then aim to identify which characteristics or land management practices are common to the soils which are more resilient.
Phone:+44 (0) 1582 763 133 ext: +44 1582 938228
Location:Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ
- Fundamental bases of biological soil resilience
Storkey, J., Macdonald, A. J., Bell, J. R., Clark, I. M. , Gregory, A. S., Hawkins, N. J., Hirsch, P. R., Todman, L. C., and Whitmore. A. P. "Chapter One-The Unique Contribution of Rothamsted to Ecological Research at Large Temporal Scales." Advances in Ecological Research 55 (2016): 3-42. doi.org/10.1016/bs.aecr.2016.08.002
Fraser, F.C., Todman, L.C., Corstanje, R., Deeks, L.K., Harris, J.A., Pawlett, M., Whitmore, A.P. and Ritz, K., (2016). Distinct respiratory responses of soils to complex organic substrate are governed predominantly by soil architecture and its microbial community. Soil Biology and Biochemistry, 103, pp.493-501.
Fraser, F.C, Corstanje, R., Deeks, L., Harris, J.A., Pawlett, M., Todman, L.C., Whitmore, A.P., Ritz, K. (2016) “On the origin of carbon dioxide released from rewetted soils.” Soil Biology and Biochemistry 101,1-5 doi:10.1016/j.soilbio.2016.06.032
Todman, L.C., et al. (2016) “Defining and quantifying the resilience of responses to disturbance: a conceptual and modelling approach from soil science.” Scientific Reports 6:28426 doi:10.1038/srep28426
Todman, L.C., et al. (2015) "Modelling the fill rate of pit latrines in Ifakara, Tanzania." Journal of Water, Sanitation and Hygiene for Development doi:10.2166/washdev.2014.082
Todman, L.C., Ireson, A.M., Butler, A.P. and Templeton, M.R. (2013) “Modelling Vapor Flow from a Pervaporative Irrigation System.” Vadose Zone Journal, 12 (4) doi:10.2136/vzj2013.05.0079
Todman, L.C., Ireson, A.M., Butler, A.P. and Templeton, M.R. (2013) “Water vapor transport in soils from a pervaporative irrigation system.” Journal of Environmental Engineering 139 (8) doi: 10.1061/(ASCE)EE.1943-7870.0000715
Mathias, S.A., and Todman, L.C. (2010) “Step-drawdown tests and the Forcheimer equation.” Water Resources Research, 46 (7) doi: 10.1029/2009WR008635