Nutrient recommendations for vegetables take into account the nutrient demand of the crop and soil analysis. Different methods are used to assess the nitrogen availability in the soil which varies in space and time. The nitrogen demand of vegetables is higher than the nitrogen uptake particularly on fields with a high level of productivity. To optimise and control nutrient applica-tion, the total amount of fertiliser applied on the whole farm is assessed. The total amount of nitrogen and phosphorous applied may not exceed 10 % of the amount recommended. Biological farms use the same amount of phosphorous, the amount of nitrogen is significantly lower compared to integrated farms. Different factors affecting the demand of nitrogen nutrition of vegetables are well known, the significance of other factors is not so well established.<br><br>There is a gap between knowledge and the implementation of this knowledge into practical fertiliser recommendations. The govern-mental authority responsible for the protection of the quality of the groundwater has establisheda program to further reduce the nitrate and phosphorous content of the drinking water by a package of measures restricting farming activities severely.
Zufferey V., Delabays N., Verdenal T., Reynard J.- S., Dienes A., Belcher S., Lorenzini F., Bieri S., Blackford M., Bourdin G., Spangenberg J.-E., Carlen C., Spring J.-L.
Reynard J.- S., Spring J.-L., Verdenal T., Zufferey V., Bourdin G., Bieri S., Carlen C., Crettenand F., Favre G.