Bernard Nicoullaud

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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(More)
During early growth, when the apical meristem of a maize plant is close to the soil surface, its temperature may be very different from air temperature. A model is proposed to estimate apex temperature from meteorological data, when the leaf area index is less than 0.5. This model is based on the energy balance of the apical meristem, considered as a(More)
We assessed nitrous oxide (N(2)O) emissions at shoulder and foot-slope positions along three sloping sites (1.6-2.1%) to identify the factors controlling the spatial variations in emissions. The three sites received same amounts of total nitrogen (N) input at 170kgNha(-1). Results showed that landscape positions had a significant, but not consistent effect(More)
The vertical distribution of maize roots was studied in four contrasting soils, (arenosols, luvisols, planosols and vertisols) by using in-situ root mapping on vertical planes. The relationship between root contact frequency and depth was different for each soil, with a relatively low field-to-field variability within each soil type. The general aspect of(More)
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(More)
A field study was conducted to quantify spatial soil variability and to analyze correlations among soil properties at different spatial scales. Soil samples from 0 to 30 cm depth were collected from two adjacent fields in the southwestern Beauce Plain (France) which consisted of Haplic Calcisols and Rendzic Leptosols. Factorial kriging analysis (FKA) was(More)
We report on the development and performance of a gas sensor based on a distributed feedback quantum cascade laser operating in continuous wave at room temperature for simultaneous measurement of nitrous oxide (N(2)O) and methane (CH(4)) concentrations at ground level. The concentrations of the gases are determined by a long path infrared diode laser(More)
Modeling nitrous oxide (N2O) emissions from agricultural soils is still a challenge due to influences of artificial management practices on the complex interactions between soil factors and microbial activities. The aims of this study were to evaluate the process-based DeNitrification-DeComposition (DNDC, version 9.5) model and modified non-linear empirical(More)
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