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| David, Christophe; Jeuffroy, Marie-Hélène. |
| Advances in scientific understanding of the plant and soil behaviour in a cultivated field led to the design of numerous soil-crop models simulating crop growth. The frequent low predictive quality of these models is linked to uncertainties in inputs, parameters and equations. The AZODYN crop model predicting wheat grain yield and grain protein content was previously developed to support decision for N management of conventional and organic wheat crops. This paper outlines a sequential approach to improve the predictions of the AZODYN model by testing various formalisms. This study is based on the comparison of 38 versions of the model assessed in multi-environment trials carried out under conventional or low-input conditions. This paper describes and... |
| Tipo: Journal paper |
Palavras-chave: Cereals; Pulses and oilseeds Composting and manuring Nutrient turnover. |
| Ano: 2009 |
URL: http://orgprints.org/19494/1/David_et_Jeuffroy%2C_2009.pdf |
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| Casagrande, Marion; David, Christophe; Etienne, Catherine; Makowski, David; Valantin-Morison, Muriel; Jeuffroy, Marie-Hélène. |
| A regional agronomic diagnosis was implemented to identify factors responsible for low values of Grain Protein Content (GPC) in a network of 35 organic winter wheat fields in South-Eastern France. The influence of water nutrition, radiation and temperature, weed density at flowering, nitrogen (N) status of crop at flowering and variety type were studied. Two statistical methods were used successively: classical linear regression and a mixing model approach based on a weighted sum of all possible linear combinations of explanatory variables. GPC was significantly related to variety type, crop N status and weed density. An analysis of variance showed that weed density was related to soil type and nitrogen supply. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Cereals; Pulses and oilseeds. |
| Ano: 2008 |
URL: http://orgprints.org/11825/1/Casagrande_11825_ed.doc |
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| Casagrande, Marion; David, Christophe; Valantin-Morison, Muriel; Jeuffroy, Marie-Hélène. |
| French organic farmers are asked to increase Grain Protein Content (GPC) of organic winter wheat to guarantee the breadmaking quality required from millers. Facing with the recent depletion of organic products, farmers also need to stabilize and increase the yield performance. The aim of our study is to give the explanations of the yield and GPC variability generally observed in organic production. A diagnostic method will be implemented on a network of ca. 10 fields per year during two crop years added with previous field network (77 fields) and experi-ments (4 experiments on cultivars). We will under-stand yield and GPC performance from environmental and agronomic conditions and relate the observed limiting factors with crop management, climatic... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Cereals; Pulses and oilseeds. |
| Ano: 2006 |
URL: http://orgprints.org/7358/1/ShortpaperMarionCasagrande.rtf |
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