Production de légumes frais de qualité spécifique (différenciée ou non) dans un contexte d'agriculture durable en Wallonie

Production of vegetables for fresh market with specific quality (differentiated or not) in the frame of sustainable agriculture in Wallonia.

Context

Agriculture in Wallonia includes a large potential for fresh vegetables crops (lettuces, carrots, onions, endives, cabbage, curled-leaved endives). To find new commercial opportunities for such crops, a way is to develop a well described and well known specific quality for Walloon vegetables production, through the set up and the respect of constraints for production and commercialisation. For different plant species, studies on the effects of agronomic factors that contribute to the quality of the products and to environmental hazards are the base of the project. Results should be integrated in the content of constraints that will be developed through consultancy services and applied by the producers.

Objectives

For each plant species, and considering climatic and soil conditions as well as factors such as location, timing of cropping and varieties, the objectives of the research in the next years will be to study: - The nitrogen plants needs as part of the crop nitrogen balance sheet, aiming to assess the N-advice to be applied at field scale. - The pattern of plant growth and the kinetics of crop nitrogen uptake to eventually modulate time and way of N fertilizer applications. - The possibilities to split N fertilizer applications, taking into account the time-course of crop nitrogen status through the use of plant or soil indicators. - The nitrogen fertilizer rate that should match optimal commercial yield level, parameters levels for the requested quality of the product and the limitation of soil mineral nitrogen residues at harvest.

Description of tasks

In 2005 and 2006, trials will be conducted in commercial fields with curled-leaved endives, onions and carrots. Increasing nitrogen fertilizer rates (split or not) and some varieties will be compared for their influence on yield, crop biomass production and nitrogen content, kinetic of plant N-uptake, leaves chlorophyll and nitrate content. Specific measurements on biomass (P, K and Ca concentrations) should be operated for some species. Quantitative and qualitative parameters of harvested products considered for their commercialisation will be assessed.

Expected results

Expected results for the first 2-years period are: - the determination of the crop nitrogen needs and the possibility to split N applications for each plant species according to cropping time and the variety; - the possibility to assess the crop nitrogen status through a quick, sensitive and early test in the course of the growing season; - for such a potential test, the set-up and the validation of threshold values to detect the need for supplementary nitrogen to apply.

Contribution

Organisation and coordination of research, trials management, results analyse and diffusion, reports, scientific and technical publications. Quality Department: NIR plant analysis for nitrogen content

Partners

Centre Interprofessionnel Maraîcher (CIM) (dir. Jean Maréchal) MRW - DGA Recherche et DGA Développement

CRAW off coordinator

GOFFART Jean-Pierre AS - Chef de Travaux Rue du Bordia, 4 B-5030 Gembloux goffart@cra.wallonie.be Tél : 00 32 (0) 81 62 50 04 Fax : 00 32 (0) 81 61 41 52