| Abstract: | Pollution of inland waters by agricultural land use is a concern in many areas of the world, and especially in arid regions, where water resources are inherently scarce. This study used physical and chemical water quality and stable nitrogen isotope (δ15N) measurements from zooplankton to examine nitrogen (N) sources and concentrations in four small lakes of Khorezm, Uzbekistan, an arid, highly agricultural region, which is part of the environmentally-impacted Aral Sea Basin. During the 2-year study period, ammonium concentrations were the highest dissolved inorganic N species in all lakes, with a maximum of 3.00 mg N l−1 and an average concentration of 0.62 mg N l−1. Nitrate levels were low, with a maximum concentration of 0.46 mg N l−1 and an average of 0.05 mg N l−1 for all four lakes. The limited zooplankton δ15N values did not correlate with the high loads of synthetic fertilizer applied to local croplands during summer months. These results suggest that the N cycles in these lakes may be more influenced by regional dynamics than agricultural activity in the immediate surroundings. The Amu-Darya River, which provides the main source of irrigation water to the region, was identified as a possible source of the primary N input to the lakes. |
| Genre: | Article |
| ProdID: | 70037662 |
| Citation Author: | Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, B. |
| Citation Contributing Office: | Nevada Water Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 368 |
| Citation Issue: | 1-3 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Biogeochemistry |
| Citation LatN: | 42.0 |
| Citation LatS: | 40.56 |
| Citation LonE: | 62.36 |
| Citation LonW: | 60.06 |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | 12 p. |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | Springer |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan; 2010; Article; Journal; Biogeochemistry; Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, B. |
| Citation Start Page: | 357 |
| Citation Volume: | 101 |
| Citation Year: | 2010 |
| Type: | citation/reference |
| Text: | Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan; 2010; Article; Journal; Biogeochemistry; Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, B. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1007/s10533-010-9509-3 |
| Date Other: | Fri, 1 Jan 2010 00:00 -0600 |
| Publisher: | Springer |
