Impact of agricultural management on soil organic matter composition and turnover

Grasslands may be beneficial for soil C storage due to their permanent soil cover and their important belowground C input. N-fertilisation, cutting and grazing regimes may influence carbon storage as well as soil organic matter turnover and greenhouse gas emissions. To assess these effects and their impact on stabilisation processes we study a longterm experimental site (SOERE ACBB) and combine analyses of microbial parameters, soil organic matter and greenhouse gas fluxes. We are also interested in the use of plants to increase soil carbon sequestration and the sustainability of agricultural systems, e.g. by the use of legumes or biodiverse mixtures in grasslands and evolutionary populations or new perennial grains in Agricultural systems (AEGES project, NewZealand project, ChangeUp project, CarouNd project, PhD and postdoc project Alexandra Crème, PhD project Aliia Gilmullina, PhD project Asma Jerray, postdoc project Charlotte Vedere).

Use of organic amendments and development of innovative organic fertilisers to increase soil ecosystem services

Intensive agriculture has led to depletion of soil organic matter contents and intensive fertiliser use raises problems of environmental pollution. On the other hand, organic waste production is increasing worldwide and population growth induces the need for increasing agricultural production. We address these problems by suggesting new ways of transformation of organic wastes into innovative organic amendments by using composting and vermicomposting in the presence of mineral and organic additives. We also investigate biochar as a new organic amendment. We study the impact of the amendments on soil biogeochemical cycling (Vermisol project, Eurochar project, PhD Phuong Ngo, PhD Christophe Naisse, PhD Justine Barthod, PhD project Patricia Poblete Grant, PhD project Marie-Liesse Aubertin, postdoc project Charlotte Vedere, postdoc project Manhattan Lebrun)

Effect of biology (plants and soil fauna) on biogeochemical cycling and organo-mineral complex formation

The formation of organic mineral complexes is an important stabilisation process, leading to long residence times of soil organic matter. The role of biological agent such as plants and soil fauna in these processes are not well understood. We address the impact of the biological agents on organomineral complex formation on a molecular level using microscale analyses (Lombricom project, Master project Tobias Lenhart, Marianna Märten, PhD project Guillaume LeMer, postdoc project Nicolas Puche, Master and PhD project Hoang Dang, U2worm project, postdoc project Chao Song, Master and PhD project Yacouba Zi)

Quantity and effect of microplastics in soil

Microplastic (MP) pollution of soil has received attention in recent years due to the fact that MP are umbiquitous in environment, although only little is know about their environmental impact. PSG has taken the lead in the establishment of a French research consortium, which seeks to quantify the presence of MP in soils receiving organic amendments in form of urban compost and to evaluate the impact of contrasting MPs on processes impacting biogeochemical cycling in soil (Plastisol project, eDip project, postdoc project Gabin Colombini, PhD project Melissa Bakhos).

Impact of climate change on biogeochemical cycling and soil functioning

Global warming and associated occurrence of extreme events have profound effects on plants, soil fauna and microorganisms, thereby influencing biogeochemical cycling. We address the effect of soil warming and occurrence of drought using field manipulative experiments. PSG is part of the global network of soil warming experiments (Deepsoil 2100) (Soilwarm project, PhD project Zulfikar Khan)

Blue carbon

Coastal ecosystems such as salt marches and mangroves store huge amounts of carbon. These systems are located at the interphase between terrestrial and marine systems and have been rarely studied up to now. We are addressing biogeochemical cycling and in particular the stabilisation processes of organic matter in the soils of these ecosystems. The processes are expected to be different as compared to the ones occurring in terrestrial ecosystems, due changeing redox conditions and tidal dynamics (MangC project, postdoc project Marie Arnaud, Master project Melissa Bakhos, Master project Marion Maceiras)