1. Nitrogen source tracing in the Choptank River Watershed Midshore Riverkeeper Conservancy University of Maryland Center for Environmental Science National Fish and Wildlife Foundation

2. Forms of Nitrogen N2N2

3. N stable isotopes: how it works + + + + + + + - - - - - - - + + + + + + + - - - - - - -

4. The 15 N: 14 N ratio can vary depending on how nitrogen is used 15 N 14 N Ratio referred to as  15 N

5. Amount of nitrogen (%N) does not equal  15 N %N  15 N %N  15 N < >

6. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation

7. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation

8. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation Biological fixation

9. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation Industrial fixation Biological fixation

10. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation Volatilization Industrial fixation Biological fixation

11. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation Denitrification Ammonium Nitrite Nitrate Volatilization Industrial fixation Biological fixation

12. Nitrogen Cycle Atmospheric nitrogen Atmospheric fixation Denitrification Ammonium Nitrite Nitrate Volatilization Industrial fixation Biological fixation

13. % Nitrogen  15 N 05 0 30 -5 5 10 15 20 25 1234 Denitrification Animal Waste Volatilization enrichment Fertilizer source Low nitrogen and activity

14. Objectives Delineate the nitrogen contribution of different activities in the Choptank River Watershed (e.g. poultry, dairy, sewage, cropping, sod, slaughterhouse) Adopt combination of water quality and nitrogen stable isotope composition in aquatic plants and water samples. Relate findings to land-use practices Identify focus areas for further work / targeting of management activities

15. Sampling Sites Easton STP Cambridge STP Denton STP Cordova Oakland Farm Colliers Farm

16. What we collected Phragmites along Choptank River –  15 N – %N Grasses in Choptank watershed –  15 N – %N Water quality – MRC – This project

17. Sample analysis

18. Denitrification Animal Waste Volatilization enrichment Fertilizer sourceLow nitrogen and activity Results

19. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity River Watershed Results

20. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity Opposite Cambridge STP Denton Tuckahoe R. Huntington Ck. Gaineys Wharf Choptank Above Tuckahoe Easton STP Results

21. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity Opposite Cambridge STP Denton Tuckahoe R. Huntington Ck. Gaineys Wharf Choptank Above Tuckahoe Easton STP Results

22. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity Oakland (corn – unirrigated /manure) Oakland (corn - irrigated) Oakland Spray irrigated dairy Cordova Ck Trib (poultry, manure, slaughterhouse) Oakland (pond grass) Oakland (manure) Cordova Ck Trib (Downstream Poultry) Colliers (corn – chicken manure) Cordova Ck (downstream slaughterhouse) Masons Branch Trib. Upstream poultry Masons Branch Trib. Downstream poultry Results

23. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity Oakland (corn – unirrigated /manure) Oakland (corn - irrigated) Oakland Spray irrigated dairy Cordova Ck Trib (poultry, manure, slaughterhouse) Oakland (pond grass) Oakland (manure) Cordova Ck Trib (Downstream Poultry) Colliers (corn – chicken manure) Cordova Ck (downstream slaughterhouse) Masons Branch Trib. Upstream poultry Masons Branch Trib. Downstream poultry Results

24. Tuckahoe Results

25. Tuckahoe Results

26. DenitrificationAnimal Waste Volatilization enrichment Fertilizer source Low nutrients and activity

27. Results

28. Oakland Pond Cordova Ck Down. Slaughterhouse Cordova Ck Down. Poultry Cordova Ck Trib (poultry, manure, slaughterhouse) Masons Branch Trib. Upstream poultry Masons Branch Trib. Downstream poultry Results

29. River Watershed Watershed is distinct whereas river is a mixing bowl

30. Summary Demonstrated the river is sink of varied catchment activities Management needs to target N and P separately. Make sure any nutrient removal process targets the relevant nutrient. Emphasis on poultry appears to be P and not N Unclear why %N is inverse of TN in the river Shift over the past 10 years in N influence in the Choptank from animal waste to mixed animal waste/fertilizer source.

31. Next steps… Follow up on the turf farm Investigate above Denton and below Cambridge Consult with other scientists about the inverse relationship with TN and %N (water problem is deposited downstream in the mud???)

32. Results fix

33. Results fix