Concerns about the presence of cadmium in food are leading to increasingly stringent maximum levels for cadmium in vegetables at European level. This can have a major impact on the agri-food sector because it makes unpolluted soils unsuitable as well for the cultivation of cadmium-sensitive crops such as salsify, carrots and spinach. Cadmium occurs naturally in every soil and is absorbed by crops through their roots. However, there is no clear link between the level of cadmium in the soil and the amount of cadmium taken up by the crops, which makes it difficult for producers to predict how much cadmium will be present in spinach or carrots after harvesting. The project aims to develop a model for Flemish agricultural soils and based on simple data (soil characteristics and climate data), that determines the probability of exceeding the maximum level for cadmium in spinach and carrots grown on a specific plot. The results of the project can be used directly by cultivation associations and by cultivation supervisors in the food processing industry.
Concerns about the presence of cadmium in food have led to the implementation of strict maximum levels for cadmium in vegetables. On contaminated soils, problems may arise with regard to the absorption and accumulation of cadmium in crops. This land is therefore not eligible for growing vegetables. However, for some highly sensitive crops, such as carrots, salsify, lettuce, spinach, etc., the problem may also arise on land with “normal” cadmium levels. In addition to salsify, carrots and spinach are the most sensitive crops with respect to increased cadmium accumulation in the plant. The question arises what the relationship is between cadmium in the environment and its subsequent presence in the harvestable product and which factors influence this relationship.
The project aims to establish a model for Flemish agricultural soils based on simple measurements/data that makes it possible to determine the probability of exceeding the maximum level for cadmium in spinach and carrots, grown on a specific plot . Soil properties, total and/or extractable metal contents, as well as meteorological parameters are examined as predictive variables in such a model.
As a result, models were developed for carrots and spinach. The models were implemented in Excel and can be used as such by cultivation associations and the food processing industry to estimate the risk of a cadmium exceedance prior to sowing and/or harvesting. In this way, the farms can carry out certain pre-harvest cultivation measures, but above all it is a tool in the decision-making process to determine whether or not to sow spinach or carrots on a specific plot in a given year. By using predictive models, farms can reduce the risk of exceeding the maximum permitted cadmium level.