NITRIC FOOD POLLUTION AS A RESULT OF INTENSIVE MINERAL NITROGEN FERTILIZATION PUBLISHEDHortensia RĂDULESCU
The study reveals the most important nitrate sources of agricultural origin which often pollutefood stuffs and drinking water. In areas with intensive nitrate fertilization and livestock breeding, cropsand depth water become overloaded with nitrates. The nitrate content of carrot, spinach, lettuce, cabbageand parsley experimentally fertilized with various doses of nitrogen was measured at their harvest. Fieldexperiments were performed treating soil with six doses of nitrogen applied as a mineral fertilizer (urea,ammonium nitrate, potassium nitrate) and organic fertilizer (manure). The nitrate content of spinach,lettuce and cabbage leafs, also carrot root and vegetative organs of parsley was determined at harvesttime. The upper and deep layers of ground water in some settlements of Banat County were also sampledand analysed for nitrates, using the Griess method (spectrophotometric method). Nitrate contamination inareas of intensive agricultural activities as well as nitric overload due to intensive animal breeding werestudied on depth water samples. The obtained results showed linear correlation between the nitrogenamount used as fertilizer or generated by intensive animal breeding and the nitrate content of vegetablesand water samples. The values of the nitrate content in vegetables altered and depended also on theanalysed vegetable species. Nitrogen added as organic fertilizer (manure) generates at harvest time lownitrate content in vegetables. Therefore the organic fertilizer should be preferred to mineral fertilization,if the agricultural technology admits it. The usefulness of the paper lies in preventing the consumer’snitric stress by food and water consumption. The importance of the obtained results consists in informingpotential consumers about the nitric accumulation prevalent in leaf and root vegetables also in depthwater resources in areas of intensive fertilization with mineral nitrogen or industrial animal breeding. Inorder to prevent high nitrate concentration in leaf and root vegetables, the nitrogen fertilizer dose to beapplied should be calculated on the basis of specific consumption of the species and also the features andfertility of the soil. The climatic conditions, the vegetation period of the crop and the harvest time are alsorelevant, since they deeply influence the reduction of nitrates.
nitrogen dose, vegetables, depth water, nitrate content, nitric overload;