The study shows that the most important nitrate sources of agriculture origin which can pollute vegetal food stuffs are leaf vegetables well known as nitrate accumulators. In areas with intensive nitrate fertilization crops become overloaded with nitrates. Therefore spinach, lettuce, cabbage, carrots and parsley, to be ingested by the consumer, were experimentally fertilized with various doses of nitrogen and than the nitrate content was measured at their harvest. The nitrate content in leafs was determined by using standard methods, as atomic absorption spectrometry (AAS), approved by Romanian STAS 784/2-2009.Field experiments took place by fertilizing soil with six doses of nitrogen applied as mineral and organic fertilizer. The obtained results indicate a direct correlation between the nitrogen amount used as fertilizer and the nitrate content of vegetables. Nitrogen given as organic fertilizer (manure) establish at harvest time low nitrate content in vegetables, unlike the treatment with mineral fertilizer. Therefore the organic fertilizer is to be chosen instead mineral fertilization if the agricultural technology admits it. The nitrate content in vegetables is variable, depending also on the analyzed vegetable species and plant parts. The importance of the established results lies in informing the consumers about the nitrate accumulation in several leaf vegetables when intensive mineral fertilization is used. In order to prevent high nitrate content in leaf vegetable, the chosen nitrogen fertilizer dose depends also on several factors like soil features, climatic conditions, vegetation period of the crop and harvest time. The climatic conditions, the vegetation period of the vegetables and the harvest time are relevant for the nitrate content, since they influence the reduction process of nitrates. The usefulness of the paper lies in preventing the ingestion of high nitrate amounts by the consumer through leaf vegetables consumption, knowing that leaf vegetables are an important source of vitamins and minerals. To prevent the toxic nitrate impact on the consumer’s health, the daily intake of nitrates by food consumption should not exceed the acceptable level established by FAO and WHO representing 3,65 mg nitrate/ kg body mass.

nitrogen dose, nitrogen fertilizer, leaf vegetables, nitrate content, nitric overload

environmental engineering

Presentation: poster