Aquatic environment

Shallow groundwater nitrogen responses to di erent land use managementsin the riparian zone of Yuqiao Reservoir in North China

LU Haiming , YIN Chengqing


Received March 16, 2007,Revised January 25, 2008, Accepted , Available online

Volume 20,2008,Pages 652-657

  • Summary
  • References
  • Related Articles
This field study investigated the nitrogen concentrations in the shallow groundwater from an ephemeral stream and four land uses: cropland, two-year restored (2yr) and five-years restored (5yr) woodlands, fishponds, and the nitrogen flux in the riparian zone of Yuqiao Reservoir. The groundwater nitrate-N concentrations in cropland were the highest among the four land uses. Total dissolved nitrogen (TDN) and nitrate-N concentrations in the 2yr woodland were significantly (p < 0.05) higher than in 5yr woodland. The lowest nitrogen concentrations were detected in fishponds. Nitrate-N was the main form in cropland and 2yr woodland, whereas both nitrate-N and dissolved organic nitrogen (DON) were the main species in 5yr woodland and fishponds. But, ammonium-N was the main form in the ephemeral stream. During the rainy season, the groundwater flow with dissolved nitrogen drains from upland into the reservoir along the hydraulic gradient. The woodland between the cropland and reservoir could act as a bu er to retain shallow groundwater nitrogen. The dominant form of ammonium-N in the groundwater TDN pool in ephemeral stream indicated that nitrogen from the village and orchard in upland flowed into the reservoir via subsurface flow. The fishpond was not an important pollution source for nitrogen transfer via shallow groundwater.

Copyright © Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.京ICP备05002858号-3