The Variance of Nitrate Nitrogen in Groundwater of Intensive Agricultural Region in Daxing District from 2005 to 2011

The groundwater sampling and nitrate nitrogen testing were carried out for 13 times from 2005 to 2011 in order to investigate the nitrate nitrogen dynamic change of groundwater in the intensive agricultural area of Daxing district and explore its control countermeasures. The results indicated that the mean value of nitrate nitrogen in groundwater of this area was 1.58 mg/L, which met the criterion of the second level water quality in national criterion of groundwater quality, and in this study area the regional anisotropy caused by nitrate in groundwater was enlarged. The average concentration of nitrate nitrogen in groundwater from grain field was significantly higher than those from orchard and the other type of field, while it was slightly higher than that from vegetable field. Mean values of nitrate nitrogen in groundwater from vegetable field had a positive linear correlation with those of whole area in different sampling times. Effective countermeasures to reduce the risk of nitrate pollution in groundwater in Daxing district should be considered including rationally using agricultural inputs in planting area with intensive agricultural activities, carrying out effective water management measures, formulating corresponding laws and rules of groundwater nitrate pollution prevention and control, reinforcing the propaganda of popular science and improving the environmental consciousness of the public.