Impacts de restrictions en eau d'irrigation sur les exploitations et les filières agricoles en Beauce

Beaucoup d’agriculteurs, comme les opérateurs des filières aval qui collectent ou transforment leur production, dépendent de l'irrigation. Or, dans de nombreuses régions du monde, structurellement ou conjoncturellement, les ressources en eau disponibles déclinent et sont soumises à des contingentements de plus en plus sévères. Cette étude vise à analyser les conséquences de scénarios de fortes baisses de la disponibilité en eau sur les stratégies des agriculteurs en termes de choix d’assolement et de mode de conduite et d’irrigation des cultures ainsi que l’effet de ces stratégies sur l’organisation de filières locales. Elle a été mise en oeuvre en France, dans la plaine de la Beauce, où une forte proportion de l'agriculture est irriguée à partir d'une ressource souterraine soumise à un dispositif de gestion volumétrique. L’évaluation des impacts de restrictions d’eau s’appuie sur une analyse économique des filières locales ainsi que sur des ateliers participatifs regroupant des agriculteurs et des opérateurs des unités aval. Les résultats montrent les effets de restrictions d’eau sur les choix d’assolement des agriculteurs, les volumes de production à l’échelle du territoire, les marges brutes des exploitations et les valeurs ajoutées des filières. / Many farmers, and the large set of downstream operators who depend on their farm products, have become depend-ent on irrigation. But, in many parts of the world, water resources are declining for structural or temporary reasons. Farmers have to reduce water consumption by growing crops with lower water requirement and apply optimal irri-gation strategies. The strategies they choose can have major consequences for downstream operators and local agro-industries. This paper analyzes the impacts and consequences of high water restrictions scenarios for farmers and the subsectors depending on their production. This approach was imple-mented in France, in the region of Beauce, where irrigation relies on groundwater use and on a volumetric management of the local aquifer. Scenarios based on two different levels of water availability reduction were assessed and strategies to face reduced water availability were analyzed for both farmers and downstream operators. The analysis was based on a technical diagnosis of the local organization, an eco-nomic analysis of value added, and participatory workshops including farmers, downstream operators and state repre-sentatives. Our analyses showed how farmers would adapt to water restriction and, depending on their choice of pro-duction, how their strategies could impact the volume of production at sub-regional level, the value added at subsec-tor level and could lead to competition between down-stream operators

Irrigation and energy: Issues and challenges

Water‐efficient agriculture has implied a large increase in energy consumption for irrigation in recent decades. In many irrigation systems, energy costs are now threatening their sustainability. However, new opportunities have arisen for the use of renewable energies in the irrigation sector. These are some of the aspects of the multifaceted multiple‐actor 'water–food–energy' nexus. Technical, economic and environmental issues are linked in many ways, involving farmers, water users' associations, energy suppliers, engineers and other stakeholders. The ICID session 'Irrigation and energy' triggered discussions on these multiple dimensions. This paper presents a synthesis of the presentations, discussions and conclusions. Four main questions are addressed: How do irrigation productivity and sustainability of water resources exploitation change when farmers have access to energy? What do we know about energy efficiency in irrigation systems, at farm and collective network levels? How can this efficiency be optimized by using advanced technologies, modelling tools, improved management? Is energy production an opportunity for irrigation systems? These questions have been posed based on multiple case studies from different parts of the world. The BRL network, in southern France, illustrates advanced strategies and opportunities to reduce energy consumption and develop energy production at a network level. General conclusions are drawn from this synthesis, illustrating trade‐offs and synergies that can be identified in the irrigation sector at different scales, while opportunities for future research are proposed

Improving survival in recurrent medulloblastoma: earlier detection, better treatment or still an impasse?

Early detection of relapse has been advocated to improve survival in children with recurrent medulloblastoma. However, the prognostic factors and the longer term outcome of these patients remains unclear. Pattern of recurrences were analysed in three consecutive protocols of the Société Française d'Oncologie Pédiatrique (1985-91). A uniform surveillance programme including repeated lumbar puncture combined with computerized tomography (CT) or magnetic resonance imaging (MRI) scan was applied for all registered patients. Forty-six out of 116 patients had progressive or recurrent disease. The median time from diagnosis to recurrence was 10.5 months and 76% relapses occurred during the first 2 years. Seventeen patients had asymptomatic relapses that were detected by the surveillance protocol. Forty-one patients were treated at time of progression. Twenty-three responded to salvage therapy and 11 achieved a second complete remission. The median survival time after progression was 5 months (<1-41 months), and only two patients remained alive at time of follow-up. Length of survival is primarily related to some specific patterns of relapse (time from diagnosis to recurrence, circumstances of relapse, extent of relapse) and to the response to salvage therapy. No evidence of long-term benefit appeared from any form of treatment

Adverse outcome of infants with metastatic neuroblastoma, MYCN amplification and/or bone lesions: results of the French Society of Pediatric Oncology

To assess the relevance of MYCN amplification and bone lesions in stage 4 neuroblastoma (NB) in infants aged <1 year, 51 infants with stage 4 NB were enrolled. Three groups of patients were defined according to the type of metastases and the resectability of the primary tumour. Group I comprised 21 infants with radiologically detectable bone lesions, Group II 22 patients with an unresectable primary tumour and Group III eight patients with only metaiodobenzylguanidine (MIBG) skeletal uptake. MYCN oncogene content was assayed in 47/51 tumours and found to be amplified in 17 (37%). The 5-year event-free survival (EFS) rate of these 51 infants was 64.1% (± 7.1%). In a univariate analysis, bone lesions, MYCN amplification, urinary vanillylmandelic/homovanillic acid ratio and serum ferritin levels adversely influenced outcome. In the multivariate analysis, radiologically detectable bone lesions were the most powerful unfavourable prognostic indicator: the EFS rate was 27.2% for these infants compared to 90% for infants without bone lesions (P < 0.0001). Our data emphasize the poor prognosis of infants affected by stage 4 NB with bone lesions, especially when associated with MYCN amplification. Given the poor results in this group whatever the treatment, new therapeutic approaches need to be investigated in the future. © 2000 Cancer Research Campaig

Incidence and prognostic value of tumour cells detected by RT–PCR in peripheral blood stem cell collections from patients with Ewing tumour

To retrospectively evaluate the incidence of tumour cell contamination of peripheral blood stem cell (PBSC) collections and to correlate these data with the clinical outcome after high-dose chemotherapy (HDCT) with stem cell rescue in patients with a high-risk Ewing tumour. Peripheral blood stem cell collections obtained from 171 patients were analysed. Tumour contamination was assessed by reverse transcriptase–polymerase chain reaction (RT–PCR). The files of 88 patients who underwent HDCT followed by PBSC reinfusion were reviewed in detail, and their outcome compared to the PBSC RT–PCR results. Seven of 88 PBSC collections (8%) contained tumour cells as detected by RT–PCR. Peripheral blood stem cells were collected after a median of five cycles of chemotherapy. No clinical factor predictive of tumour cell contamination of PBSC harvest could be identified. Event-free survival (EFS) and overall survival (OS) of the whole study population were 45.3 % and 51.8 % at 3 years from the date of the graft, respectively. Forty-five patients relapsed with a median time of 15 months after graft, only four of whom had tumour cell contamination of the PBSC harvest. Tumour cell contamination of PBSC collection is rare and does not seem to be associated with a significantly poorer EFS or OS in this high-risk population

Evaluation des impacts de restrictions d’eau pour l’usage agricole Une démarche à l’échelle des filières de production

Beaucoup d’agriculteurs, comme les opérateurs des filières aval qui transforment leur production, dépendent aujourd’hui des ressources en eau souterraine. Or, dans de nombreuses régions du monde, en climat aride comme tempéré, les nappes souterraines sont surexploitées et les ressources disponibles déclinent. Les agriculteurs sont alors confrontés à une pression croissante pour préserver cette ressource. Cette situation les amène d’une part, à économiser l’eau en mettant l’accent sur des productions moins consommatrices, d’autre part, à mieux valoriser les quantités utilisées. Plusieurs stratégies sont envisageables comme modifier les choix d’assolement ou adapter les modes de conduite des cultures. Ces stratégies peuvent avoir des conséquences importantes sur l’organisation des filières aval. Cette communication propose les bases d’une démarche visant à analyser les conséquences de fortes restrictions d’eau sur l’organisation de filières locales. Elle a été mise en oeuvre en France, sur le cas de la nappe de Beauce, en partenariat avec la profession agricole, les opérateurs des unités de transformation et les représentants de l’Etat. Elle permet d’analyser les adaptations et les stratégies de chacun face à des baisses de volumes d’eau disponibles. Elle met en évidence les interactions entre les opérateurs d’une même filière et les interactions entre différentes filières. Many farmers, and the large set of downstream operators who depend on their farm products, have become dependent on groundwater resources. Although overexploitation of groundwater resources is far from being a universal phenomenon, it can be observed not only in arid areas but also in the areas with a temperate climate. In regions where groundwater resources are declining, farmers have to reduce water consumption by growing crops with lower water requirement, or apply optimal irrigation strategies. The strategies they choose can have major consequences for downstream operators and local agro- industries. This paper presents an approach to analyze the impacts on and consequences of high water restrictions for the subsectors. This approach was implemented in the region of Beauce, in France, in collaboration with farmers, downstream operators and state representatives. Adaptations and strategies to face reduced water availability were analyzed in economic and technical terms for both farmers and downstream operators. Participatory workshops brought together different downstream operators who could become competitors for the same resource and highlighted interactions between operators in the same subsector as well as interactions between different sectors

Restrictions d’eau pour l’usage agricole sur la nappe de la Beauce (France) : quels sont les impacts sur les exploitations agricoles et sur le secteur agro-alimentaire ?

International audienceMany farmers, and the large set of downstream operators who depend on their farm products, have become dependent on groundwater resources, which are declining in many parts of the world. Farmers have to reduce water consumption by growing crops with lower water requirements, or apply optimal irrigation strategies. The strategies they choose can have major consequences for downstream operators and agro-industries. This paper presents an analysis of the impacts on, and consequences of, high water restrictions for the subsectors. The analysis was conducted in collaboration with local stakeholders in the region of Beauce, France. Adaptations and strategies to face up to reduced water availability were analysed in economic and technical terms for both farmers and downstream operators. Participatory workshops brought together different downstream operators who could become competitors for the same resource and highlighted interactions between operators in the same subsector as well as interactions between different sectors