FR-2 :: Agricultural production and climate

Agriculture plays an important role in the environmental evolution at a global scale; it contributes to GES emissions together to potential carbon storage. Numerous pressures such as pesticides use, fertilizers use, and tillage have an impact on soil and groundwater quality, on its productivity. Organic matter and in particular organic carbon improve soil fertility and its stability and contribute also to control atmospheric carbon emissions. In France, organic carbon content decrease of 9 % in agricultural soil due to ecosystems evolution, conversion of grassland to arable land, agricultural practices changes (CGDD, 2015). Agricultural practices such as tillage, affect mostly some microfauna and fauna classes (microscopic fungi, earthworms) which are essential to soil functioning toward its structuration. Mean excess of nitrogen is estimated to 902 000 tons en 2010 en France with significant disparity between regions and crop type. Nowadays, forest soil management involve the adaptation of silvicultural objectives to the local context in order to preserve soils by limitation practices impacts to an acceptable goal because practices changes and wood demand does not allow, in some cases, a sustainable management without input or compensatory works. Compaction risk mapping of French soils show that that compaction mainly due to agricultural and forestry mechanisation and is very high in 15 % of agricultural soil under wheat crop and one third of French agricultural soil has a high risk of soil compaction with again high spatial disparities. One of the specificities of France is the opportunity to access to different areas with wide range of climate, soil type, crop type, biodiversity, and local constraints (metropolitan France and French overseas). Proper functioning of agricultural, forest and natural’s soils will be ensure by providing to the relevant managers, knowledge and decision making tools to allow them to adapt relevant practices for a better preservation of soil and to improve soil state, using indicative political or economic instruments
Specific research questions (following the conceptual model of INSPIRATION)
• Need to review methodological approach for the determination of water retention in soil under various pedo-climatological context and various scales (from the plot to the territory).
Why: It is necessary for a better management of soil.
• Development of soil mapping at the local scale.
Why: for the development of strategic tools better adapted to local diversity, complex development operations, but also to changes in the time of their territory.
• Develop prospective approaches, modelling for scenarios of evolution building, mechanisms involved
Why: to be able to support change, inform decision to be taken for changing practice patterns.
Natural capital
• Understand soil carbon dynamic in the critical zone, biogeochemical mechanisms involved using integrated approaches and new tools.
Why: To improve carbon storage in soils (4 per 1000 program launch by French Ministry of Agriculture) and to better understand how climate change impacts soil organic carbon dynamics.
• Need to research substitution solutions to conventional herbicides, insecticides and fungicides, antiobiotics.
Why: To limit in the future further pollution of surface water and groundwater, soils and food.
• Need to research alternative solution to inorganic nitrogen and phosphorus fertilization.
Why: To limit the cost of treatment of contaminated environment (such as water).
Land management
• Develop a new agricultural model, with an evaluation of alternatives cultural practices developed at a local scale to be translated at a national scale, taking into account territorial specificities for cultural practices implementation.
Why: There is a societal challenge for an agriculture turned toward research of new practices and production systems more efficient on economic, environmental and social aspects.
• Integrate microbial biodiversity preservation in soil management to maintain essential soil function (carbon and nitrogen cycles).
Why: Need to preserve biodiversity and soil functions.
• Need for knowledge about processes and factors controlling organic matter storage and fluxes in contrasted landscape.
Why: to be implemented in management strategies of organic matter at agricultural landscape scale (equilibrium between carbon storage and nutriments availability for plants).
Net Impact
• Understand nitrogen impacts under its various forms in order to quantify involved processes and spatial interactions implied in the nitrogen cascade, based on long term monitoring sites.
• Why: There is a need for innovative mitigation strategies of nitrogen loss and agricultural production system adaptation. Most long term experiments show that nitrogen surplus generates high emissions of N2O in the atmosphere (with high warming potential).
• Need to understand mechanisms controlling natural nanoparticles reactivity in order to predict their transfer along the critical zone.
Why: Reduce the exposure risk potential for humans and animal.
• Develop innovative technologies of soil tillage and evaluate the gain in terms of biodiversity preservation, efficiency, soil compaction.
Why: There is a societal challenge to be addressed in order to facilitate re-use of treated soils in planning for and managing urban development.
• Requirement of decision making indicators to evaluate and adapt practices which could impact fertility of forest lands.
Why: To improve knowledge for a better management of forests soils in relation to climate change.
• Requirement of decision making tools to adapt forest to climate change: need to know soil capabilities (especially available water storage capacity) and autecology of forest species in the aim to have a good adequation between environmental characteristics and selected species ecology to adapt to current impacts of a changing climate.
Why: To prevent forest species vulnerability to climate change and in particular to water scarcity.