G. Gosse - Academia.edu (original) (raw)

Papers by G. Gosse

Research paper thumbnail of Development and evaluation of a CERES-type model for winter oilseed rape

Field Crops Research, 1998

Because of its large N fertiliser requirements and long growth cycle, winter oilseed rape Brassic... more Because of its large N fertiliser requirements and long growth cycle, winter oilseed rape Brassica napus L. is considered to expose its environment to substantial risks of N losses. Soil-crop models provide unique tools to analyse such impacts, with an accuracy that primarily relies on the simulation of crop C and N budgets. Here, we describe a model simulating the growth and development of oilseed rape that was adapted from CERES-N Maize and a previously existing rape model. In addition to its soil components, the model, called CERES-Rape, has modules for crop phenology, net photosynthesis, leaf area development and grain filling, as influenced by crop N status. A new feature compared to previous rape models is the ability to predict the crop's C and N budgets throughout its growth cycle, including losses from leaves by senescence. It also contains a mechanistic description of N translocation from vegetative parts to pods and grains after the onset of flowering. The model has been calibrated on a one-year experiment with three fertiliser N levels conducted in France, and subsequently tested on a similar experiment from Denmark for which no parameters were adjusted. In the vegetative phase, the time course of biomass and N accumulations in the various plant compartments was well simulated, with predicted values falling within one or two standard deviations from the mean in the measurements, except for the low-N treatments for which the high rates of leaf senescence could not be mimicked. After the onset of flowering, some bias appeared in the simulation of crop N uptake which impaired the predictions of final grain N yields. Simulated grain dry matter yields matched observations within "15% for the calibration data set, but were over-estimated by a factor of 2 for the other data set. Despite the above shortcomings, the simulation of fertiliser effects on the dynamics of crop N uptake and dry matter was judged sufficiently satisfactory to allow an investigation of N losses from rapeseed-cropped soils with the CERES-Rape model. q 1998 Elsevier Science B.V. () B. Gabrielle et al.r Field Crops Research 57 1998 95-111 96 () B. Gabrielle et al.r Field Crops Research 57 1998 95-111 98 () B. Gabrielle et al.r Field Crops Research 57 1998

Research paper thumbnail of Simulation of carbon and nitrogen dynamics in arable soils: a comparison of approaches

European Journal of Agronomy, 2002

Although mechanistic soil-crop models are increasingly accepted as valuable tools in analysing ag... more Although mechanistic soil-crop models are increasingly accepted as valuable tools in analysing agronomical or environmental issues, potential users are faced with an equally increasing number of available models. In principle, model selection should be based on a rational assessment of its merit with respect to the objectives pursued. Such information may be obtained by comparing the ability of candidate models to predict given sets of experimental data. However, because the basic components of soil-crop models interact strongly in producing model outputs, little can be drawn as to the validity of the approaches used for these particular components.

Research paper thumbnail of Total costs and benefits of biomass in selected regions of the European Union

Energy, 2000

The paper describes results of the BioCosts project in which a comprehensive analysis of the econ... more The paper describes results of the BioCosts project in which a comprehensive analysis of the economic and environmental performance of the energy use of biomass was carried out for selected existing facilities throughout the European Union. It is demonstrated that the appropriately organized use of biofuels has significant environmental advantages compared to the use of fossil fuels. Mitigation of global warming is the largest single incentive to use biofuels. However, only a few technologies are economically competitive under prevailing conditions, while others lead to up to 100% higher energy production costs than fossil fuels. Employment effects of using biofuels are small but positive.

Research paper thumbnail of Water and nitrate budgets in a rendzina cropped with oilseed rape receiving varying amounts of fertilizer

European Journal of Soil Science, 1998

Pollution of the environment by nitrogen (N) has emerged as a serious concern in agriculture, esp... more Pollution of the environment by nitrogen (N) has emerged as a serious concern in agriculture, especially in the case of crops such as oilseed rape. To assess the effect of N fertilization on N dynamics, the movements of water and nitrate were determined in a rendzina near Châlons-en-Champagne (eastern France) cropped with oilseed rape with three levels of fertilizer N and in a bare control. From in situ micrometeorological measurements, actual evapotranspiration rates were computed with an energy budget and used to calibrate an evapotranspiration model based on meteorological data and crop leaf area index. Water flow below 120 cm was then deduced from periodic measurements of soil moisture contents and precipitation, and the associated nitrate leaching fluxes were calculated from the NO 3 concentration measured at the same depth. Denitrification rates and ammonia volatilization were monitored in the field after fertilizer applications, and crop assimilation of nitrogen was determined frequently during the growth cycle. A nitrate budget gave an approximation of the in situ net mineralization fluxes.

Research paper thumbnail of Development and evaluation of a CERES-type model for winter oilseed rape

Field Crops Research, 1998

Because of its large N fertiliser requirements and long growth cycle, winter oilseed rape Brassic... more Because of its large N fertiliser requirements and long growth cycle, winter oilseed rape Brassica napus L. is considered to expose its environment to substantial risks of N losses. Soil-crop models provide unique tools to analyse such impacts, with an accuracy that primarily relies on the simulation of crop C and N budgets. Here, we describe a model simulating the growth and development of oilseed rape that was adapted from CERES-N Maize and a previously existing rape model. In addition to its soil components, the model, called CERES-Rape, has modules for crop phenology, net photosynthesis, leaf area development and grain filling, as influenced by crop N status. A new feature compared to previous rape models is the ability to predict the crop's C and N budgets throughout its growth cycle, including losses from leaves by senescence. It also contains a mechanistic description of N translocation from vegetative parts to pods and grains after the onset of flowering. The model has been calibrated on a one-year experiment with three fertiliser N levels conducted in France, and subsequently tested on a similar experiment from Denmark for which no parameters were adjusted. In the vegetative phase, the time course of biomass and N accumulations in the various plant compartments was well simulated, with predicted values falling within one or two standard deviations from the mean in the measurements, except for the low-N treatments for which the high rates of leaf senescence could not be mimicked. After the onset of flowering, some bias appeared in the simulation of crop N uptake which impaired the predictions of final grain N yields. Simulated grain dry matter yields matched observations within "15% for the calibration data set, but were over-estimated by a factor of 2 for the other data set. Despite the above shortcomings, the simulation of fertiliser effects on the dynamics of crop N uptake and dry matter was judged sufficiently satisfactory to allow an investigation of N losses from rapeseed-cropped soils with the CERES-Rape model. q 1998 Elsevier Science B.V. () B. Gabrielle et al.r Field Crops Research 57 1998 95-111 96 () B. Gabrielle et al.r Field Crops Research 57 1998 95-111 98 () B. Gabrielle et al.r Field Crops Research 57 1998

Research paper thumbnail of Simulation of carbon and nitrogen dynamics in arable soils: a comparison of approaches

European Journal of Agronomy, 2002

Although mechanistic soil-crop models are increasingly accepted as valuable tools in analysing ag... more Although mechanistic soil-crop models are increasingly accepted as valuable tools in analysing agronomical or environmental issues, potential users are faced with an equally increasing number of available models. In principle, model selection should be based on a rational assessment of its merit with respect to the objectives pursued. Such information may be obtained by comparing the ability of candidate models to predict given sets of experimental data. However, because the basic components of soil-crop models interact strongly in producing model outputs, little can be drawn as to the validity of the approaches used for these particular components.

Research paper thumbnail of Total costs and benefits of biomass in selected regions of the European Union

Energy, 2000

The paper describes results of the BioCosts project in which a comprehensive analysis of the econ... more The paper describes results of the BioCosts project in which a comprehensive analysis of the economic and environmental performance of the energy use of biomass was carried out for selected existing facilities throughout the European Union. It is demonstrated that the appropriately organized use of biofuels has significant environmental advantages compared to the use of fossil fuels. Mitigation of global warming is the largest single incentive to use biofuels. However, only a few technologies are economically competitive under prevailing conditions, while others lead to up to 100% higher energy production costs than fossil fuels. Employment effects of using biofuels are small but positive.

Research paper thumbnail of Water and nitrate budgets in a rendzina cropped with oilseed rape receiving varying amounts of fertilizer

European Journal of Soil Science, 1998

Pollution of the environment by nitrogen (N) has emerged as a serious concern in agriculture, esp... more Pollution of the environment by nitrogen (N) has emerged as a serious concern in agriculture, especially in the case of crops such as oilseed rape. To assess the effect of N fertilization on N dynamics, the movements of water and nitrate were determined in a rendzina near Châlons-en-Champagne (eastern France) cropped with oilseed rape with three levels of fertilizer N and in a bare control. From in situ micrometeorological measurements, actual evapotranspiration rates were computed with an energy budget and used to calibrate an evapotranspiration model based on meteorological data and crop leaf area index. Water flow below 120 cm was then deduced from periodic measurements of soil moisture contents and precipitation, and the associated nitrate leaching fluxes were calculated from the NO 3 concentration measured at the same depth. Denitrification rates and ammonia volatilization were monitored in the field after fertilizer applications, and crop assimilation of nitrogen was determined frequently during the growth cycle. A nitrate budget gave an approximation of the in situ net mineralization fluxes.