Context
This project has been developed in regard to the problems pointed out by a previous research project entitled « Production de légumes frais de qualité spécifique (différenciée ou autre) dans un contexte d’agriculture durable en Wallonie [Specific quality fresh-market vegetables production in a context of sustainable agriculture in Wallonia] (funded by DGARNE – D31/1145) », which was carried out at the CRA-W from 2005 till 2010. In that project, it appeared clearly and repeatedly that soils used for fresh-market vegetables production were characterized by high to very high amounts of inorganic nitrogen, at any time of the year. Recorded values of N concentration, which were generally widely higher than those in main crop productions, ranged from 100 to sometimes 700 kg of N/ha in the 0 to 90 cm soil layer. At this time, only one reference value for Potentially Leachable Nitrogen (PLN) is annually established for vegetable crops in the context of the PGDA in Wallonia. Since 2007, this value ranged from 120 to 180 kg of N/ha in November and from 120 to 140 kg of N/ha in December, considering the 20% tolerance used by the scientific management structure of the PGDA. These standards concern almost exclusively vegetables for industry (spinach, canned peas, green beans, broad beans, carrots) involved in classic rotations including main crop productions such as cereals and sugar-beet. Fresh-market vegetables crops are not yet concerned by such standards. However, if this case appeared, it would lead in most cases to penalties for producers, which may also have to face high difficulties to integrate the PGDA standards and constraints. In this context, in order to maintain Walloon fresh-market vegetables production sector ecologically and economically sustainable, a reflection on specific PLN standards for this sector has been started in close collaboration with the PGDA management structure. In the same way, it is essential that good agricultural practices, adapted to those standards, are identified and recommended in order to increase producers awareness of their specific situation.Objectives
This project is based on three objectives:1. To characterize as completely as possible the traits of the Walloon fresh-market vegetables production sector which are directly or indirectly linked to nitrogen fertilization management and the relative environmental impacts (risk of nitrate groundwater pollution in particular).
2. To identify and to recommend good agricultural practices at the scale of the vegetable crop rotation that will allow producers to respect the PGDA requirements in a near future.
3. To initiate a reflection about the possibility to establish specific PLN standards for the fresh-market vegetables sector by the Walloon Administration, in close collaboration with the PGDA management structure.
Expected results
• Detailed characterization of fresh-market vegetables production systems in Wallonia;• Identification of agronomical practices to ban or, on the contrary, to promote in order to restore satisfactory nitrogen amounts in soils in order to maintain agriculture and horticulture in Wallonia sustainable;
• A progress in the reflection about the pertinence to establish specific APL standards for fresh-market vegetables crops in close collaboration with the PGDA management structure in Wallonia.
Contribution
Project coordination and execution.Partners
• The Centre Pilote Maraîcher (coordinated by the CIM asbl)• The PGDA management structure in Wallonia (Grenera, Nitrawal)
• Agricultural Systems, Territory and Information Technologies Research Unit of CRA-W (U13)
Cooperation with FWH, Bioforum, VEGEMAR, CEB
Funding
- DGARNE
