Healthy soils for sustainable agriculture: the role of SOM
3–7 September 2017 • Rothamsted Research • Harpenden (United Kingdom)
Chair: Iain Hartley (University of Exeter, UK)
Improved understanding of links between carbon and nutrient cycling is essential for predicting how agricultural and natural ecosystems will respond to global change. Soil nutrient availability can directly influence microbial activity, substrate-use efficiency, and decomposition rates, while changes in the stoichiometry of organic matter inputs may affect the decomposition of pre-existing SOM. Equally, the release of nutrients into the soil matrix during decomposition is essential for maintaining agricultural/ecosystem productivity. This release also plays a key role in controlling the potential for aqueous and gaseous nutrient losses, thus influencing greenhouse gas emissions and water quality. Ultimately the impacts of land-use change, climate change and elevated CO2 on rates of decomposition and SOM storage will be strongly influenced by the interactions between carbon and nutrient cycling. For this reason, many soil, ecosystem and Earth system models now constrain C cycle projections using nutrient-cycle dynamics. Recent developments in the use of isotopic techniques, improved measurements of microbial growth and activity, in addition to substantive model advances make this a dynamic and exciting research area.
This session invites submissions that focus directly on how links between carbon and nutrient cycling affect decomposition, with empirical, modelling, and theoretical contributions all being welcomed. Topics relevant to this session include, but are not limited to: 1) studies of how nutrient availability affects decomposition rates, including stoichiometric controls over soil organic matter priming effects; 2) the investigation of how the stoichiometry of organic matter inputs affects the retention or loss of nutrients; 3) the determination of how microbial activity, growth and carbon-use efficiency is controlled by the stoichiometry of organic matter; 4) investigations of the extent to which links between nutrient and carbon cycling, and between decomposition rates and plant productivity, control the effects of global change on soil carbon storage.
It is hoped that this session will have both 'blue skies' and applied components, and will bring together scientists working in contrasting environments from natural ecosystems to intensive agriculture, across a range of climatic conditions and geographical areas.