Evaluation of nitrate concentration in the groundwater resources of gorgan

Nitrogen is vital for plants and influences the amount as well as the quality of yield. However, in the absence of proper management, it’s excessive in the water resources could have negative impact on water quality and may cause environmental as well as health complications. To evaluate the nitrate concentrations in groundwater resources in Gorgan area, north of Iran, 47 water samples were taken from different groundwater resources of shallow and deep wells as well as streams. The results showed that nitrate concentrations varied from 0.44 to more that 36 mgL- 1showing different pattern in different resources. In deep wells (wells with the depth of more than 50 meter), nitrate concentrations varied from 1.77 to 12.4 mgL-1 with an average of 5.8 while nitrate concentrations in shallow wells (wells with the depth of less than 50 meter) varied from 0.44 to 36.32 with an average of 13.37 mgL-1 . The corresponding data for streams was found to be varied from 3.54 to 27.9 mgL-1 with an average of 15.84. The results showed that nitrate concentrations was clearly greater in shallower groundwater resources compared to deeper ones showing increase of nitrate accumulation risks due to intensive agricultural activities in these area. The trends of nitrate accumulation showed that water resources is becoming more susceptible since they are the main drinking as well as agricultural source of water in the area. It seems that proper management in terms of fertilizers use and irrigation would be necessary to decrease the risk of nitrate accumulation in water with more emphasis to shallow water resources in the area