Comparison of nitrate content in soil of vegetables farms in Tehran
Author: Parisa Ziarati
Category: Pharmacy
Abstract:
Nitrate is found naturally in foods and in high concentrations in certain vegetables. Nitrogen is the main limiting factor for most field crops, and nitrate is the major from of nitrogen absorbed by crop plants. Farmers often use nitrogen fertilizers to increase crop yields. Nitrate itself is relatively non-toxic but its metabolites may produce a number of health effects. In our studies (in the South of Tehran), farmers use higher amounts of fertilizers than they should, either due to their ignorance, or because they want to increase their production quickly when the prices of their products in markets are high. The goal of this survey was to demonstrate the effects of environmental factors such as soil quality, as well the effect of farming practices and fertilizers types and amounts, on nitrate content in lettuce and spinach. In winter, spring and summer 2011 five conventional and greenhouse farms in the south of Tehran were chosen for the field survey. 150 lettuce plants and 60 spinach plants from 2 to 6 locations were sampled. A pair of conventional and greenhouse fields that have been managed by the same grower was selected to compare the effect of farming practices on nitrate content in Romania lettuce, on the other hand 3 farms compare with each other due to the kind of fertilizers using. All fields are located in the south of Tehran, Baghershahr and Share-ray. The results of the greenhouse spinach fields survey show that not only the kind of greenhouse fertilizers applied, but also soil characteristics, can significantly affect nitrate levels in plants. spinach grown using cow manure tended to contain higher nitrate that spinach grown using compost.
Keywords: nitrate content soil vegetables farms Tehran
