Modelling nitrous oxide emissions from cropland at the regional scale

Arable soils are a large source of nitrous oxide (N2O) emissions, making up half of the biogenic emissions worldwide. Estimating their source strength requires methods capable of capturing the spatial and temporal variability of N2O emissions, along with the effects of crop management. Here, we applied a process-based model, CERES, with geo-referenced input data on soils, weather, and land use to map N2O emissions from wheat-cropped soils in three agriculturally intensive regions in France. Emissions were mostly controlled by soil type and local climate conditions, and only to a minor extent by the doses of fertilizer nitrogen applied. As a result, the direct emission factors calculated at …

Bilan et perspectives des deux écoles techniques sur l'analyse des gaz

Résumé. L'analyse des gaz est utilisée notamment pour des recherches concernant l'atmosphère, le sol, les plantes, les animaux, l'humain et les composés volatils dans les aliments. L'analyse des gaz présente une pluralité de domaines d'application, d'espèces gazeuses à analyser, de gammes de concentrations ainsi que de techniques de mesure. C'est à l'occasion des Journées de la Mesure et de la Métrologie de 2006 que le besoin d'une école thématique portant sur la mesure et la métrologie appliquées à l'analyse des gaz a été exprimé. Deux écoles ont été organisées pour répondre aux besoins, la deuxième (2011) ayant bénéficié des enseignements tirés de la première (2009) suite à l'évaluation a…

Predicting in situ soil N2O emission using NOE algorithm and soil database

This paper presents a new algorithm, Nitrous Oxide Emission (NOE) for simulating the emission of the greenhouse gas N2O from agricultural soils. N2O fluxes are calculated as the result of production through denitrification and nitrification and reduction through the last step of denitrification. Actual denitrification and nitrification rates are calculated from biological parameters and soil water-filled pore space, temperature and mineral nitrogen contents. New suggestions in NOE consisted in introducing (1) biological site-specific parameters of soil N2O reduction and (2) reduction of the N2O produced through nitrification to N2 through denitrification. This paper includes a database of 6…

A priori parameterisation of the CERES soil-crop models and tests against several European data sets

Mechanistic soil-crop models have become indispensable tools to investigate the effect of management practices on the productivity or environmental impacts of arable crops. Ideally these models may claim to be universally applicable because they simulate the major processes governing the fate of inputs such as fertiliser nitrogen or pesticides. However, because they deal with complex systems and uncertain phenomena, site-specific calibration is usually a prerequisite to ensure their predictions are realistic. This statement implies that some experimental knowledge on the system to be simulated should be available prior to any modelling attempt, and raises a tremendous limitation to practica…

Simulation of nitrous oxide emissions from wheat-cropped soils using CERES

Estimation of nitrous oxide (N2O) emissions from arable soils, in relation to crop fertilization, is essential to devise strategies to mitigate the impact of agriculture on global warming. This paper presents the development and test of a N2O model resulting from the linkage of a dynamic soil-crop simulation model (CERES) with two sub-models of N2O production and reduction in soils. These sub-models (NOE and NGAS) account for both the nitrification and denitrification pathways. The resulting models (CERES–NOE and CERES–NGAS) were tested against experimental data collected on three contrasting wheat-cropped soils representative of the Beauce agricultural region in France. Although the input …

Sources et puits de gaz à effet de serre (CO2, CH4, N2O) en prairie pâturée et stratégies de réduction

National audience

La mesure des flux turbulents

National audience

Sol et changement climatique

Soilμ3d project: emergent properties of soil microbial functions from 3d modelling and spatial descriptors of pore scale heterogeneity

International audience; The reduction of greenhouse gas emissions by improving the efficiency of agricultural systems through robust ecologically-based management practices represents the most important challenge facing agriculture. Models are needed to evaluate the effects of soil properties, climate, and agricultural management practices on soil carbon and on the nitrogen transformations responsible for GHG emissions. Models of Carbon and nitrogen cycles in soils need improvements so they can provide more accurate and robust predictions. They use empirical functions which account for the different environmental factors that affect microbial functions. However, these types of function have…

Modélisation du bilan environnemlental d'une culture de colza

International audience