Examining wheat yield sensitivity to temperature and precipitation changes for a large ensemble of crop models using impact response surfaces

Impact response surfaces (IRSs) depict the response of an impact variable to changes in two explanatory variables as a plotted surface. Here, IRSs of spring and winter wheat yields were constructed from a 25-member ensemble of process-based crop simulation models. Twenty-one models were calibrated by different groups using a common set of calibration data, with calibrations applied independently to the same models in three cases. The sensitivity of modelled yield to changes in temperature and precipitation was tested by systematically modifying values of 1981-2010 baseline weather data to span the range of 19 changes projected for the late 21st century at three locations in Europe

Wheat yield sensitivity to climate change across a European transect for a large ensemble of crop models

The sensitivity of a 26 member ensemble of process based wheat simulation models to perturbations in baseline temperature and precipitation was examined to construct impact response surfaces (IRS) of simulated yields

Probabilistic assessment of adaptation options from an ensemble of crop models: a case study in the Mediterranean

Effective adaptation of agricultural systems to climate change has to: Consider local specificities; provide sound and practical information and deal with the uncertainty We present a methodology for assessing different aspects of adaptation. Our study case is adaptation of winter wheat in the Mediterranean

Model inter-comparison on crop rotation effects ? an intermediate report

Data of diverse crop rotations from five locations across Europe were distributed to modelers to investigate the capability of models to handle complex crop rotations and management interactions

Modeling tiller density, growth, and yield of mediterranean perennial grasslands with STICS

International audienceA generic crop model (STICS) was adapted (STICS–Grassland) to model growth, yield, and environmental impacts of grasslands in France. It is a semimechanistic model combining equations of physiological processes and mathematical relationships between processes in a daily time step. The Information et Suivi Objectif des Prairies (ISOP; Grassland Information and Objective Survey) application was developed to estimate and map the real-time status of grass growth and forage production in the 200 forage regions of France, to help decision makers anticipate forage availability in case of severe defi cits. Initially, the model could not simulate long, severe droughts typical of mediterranean regions when plant and tiller densities are significantly reduced. A tiller density module models the dynamics of tiller death during droughts. Since STICS is based on the concept of a mean plant (tiller) covering the whole fi eld, variability was introduced through a ã law distribution of transpiration defi cit by tiller, a threshold value imposing desiccation, and death to tillers reaching this level. Its second part generates incomplete or total recovery of tiller density through new tillering in the next wet season. Species and contrasting groups of cultivars within species can be characterized with a limited number parameter

Modèle pour simuler la dynamique de tallage des graminées fourragères pérennes sous forte sécheresse méditerranéenne

International audienceThe STICS crop model is used to simulate growth and forage production of grass pastures in cool temperate conditions (INRA France, www.avignon.inra.fr/stics/). To extend it to Mediterranean areas and to use it to anticipate future effects of the global warming, its forecasting performances during hot dry summers need to be improved, especially by taking into account variations of plant and tiller densities. The adapted formalism dealt with four successive phases: (a,b) cessation of leaf growth and plant development, followed by progressive lamina senescence, computed as a function of soil water deficit; (c) progressive tiller mortality, as a function of the actual/potential evapotranspiration ratio at individual tiller level; and (d) sward growth and tillering rates after autumn rainfalls, as a function of surviving tiller density, remaining leaf area index, and plant reserves at the end of the drought period. The model will be parameterized and tested for different species and types of cultivars. Future developments will aim to simulate the evolutions of plant densities of bi- or tri-specific mixturesUn modèle d'estimation de la croissance des prairies, incluant la variation de peuplement de talles, est un outil important pour anticiper et gérer les situations de crises ou l'effet du changement climatique. Pour disposer d'un tel modèle dans le cas des prairies monospécifiques en conditions méditerranéennes, nous avons ajouté un module de dynamique de talles au modèle de culture ST/CS, déjà validé pour les prairies de graminées en climat tempéré (INRA France, www.avignon.inra.fr/stics/). Les formalismes modifiés décrivent quatre étapes successives: (a, b) arrêt de l'allongement foliaire et du développement, puis sénescence foliaire, en fonction du déficit hydrique; (c) mortalité progressive des talles, en fonction du ratio "évapotranspiration réelle / évapotranspiration potentielle" ; et (d) reprise et retallage après les pluies d'automne, en tenant compte d'un potentiel de reconstitution. Le modèle sera paramétré pour différentes espèces et types variétaux. Les travaux futurs viseront à simuler le fonctionnement pluriannuel de prairies plurispécifiques en conditions méditerranéenne

Sustainable intensive agriculture: evidence from aqueous geochemistry

International audienceGeochemical and crop models allow for simulating the concentration of irrigation water (Durance River) by evapo-transpiration, equilibration with soil pCO 2 , dissolution / precipitation of calcite, dissolution of fertilizers (P-K, no N), and apatite precipitation. Nutrient absorption is simulated as removal of the corresponding ions from the solution. The results show that the crop system in the Crau plain has thus protected and ameliorated soils since the XVI th century, while sustaining production of high quality crops and a correct income for farmers. This has been made possible by investments in water control (irrigation and drainage). It is now endangered by urban sprawl

Rôle de la composition de l'eau d'irrigation, des interactions avec les constituants des sols et de l'absorption de nutriments dans la protection de la qualité de la nappe de la Crau et des sols - un exemple ancien d'agriculture durable.

International audienc