1 / 30

Nitrogen cycle

Nitrogen cycle. Biogeochemistry October 17, 2005 Maria Moskalenko, Gretchen Miles, Emily Paduano, Jaconette Mirck. Outline. Background Information on N Papers: Kaiser, 2001. The Other Global Pollutant Agriculture: fertilizer & food Mitsch, 2001. Reducing N loading to Gulf

chelsea-burns
Download Presentation

Nitrogen cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nitrogen cycle Biogeochemistry October 17, 2005 Maria Moskalenko, Gretchen Miles, Emily Paduano, Jaconette Mirck

  2. Outline • Background Information on N • Papers: • Kaiser, 2001. The Other Global Pollutant • Agriculture: fertilizer & food • Mitsch, 2001. Reducing N loading to Gulf • Mississippi River-hypoxia • Solutions to N-pollution • Driscoll, 2003. N Pollution in Northeast US • Atmospheric Inputs • Estuaries • Models • Discussion

  3. Nitrogen Forms, Phases and Oxidation States * * * NOx, greenhouse gases

  4. Nitrogen the other global pollutant (Kaiser, 2001) • Essential element for growth/primary production • Surplus nitrogen = pollutant • Sources: • Fertilizer • Fossil fuels • Results in various problems: • Algal bloom • Greenhouse gas • Ozone

  5. Solutions • Increase requirements for fossil fuels • Smaller cars • Hybrids • Eat less meat to reduce food of live stock • Less manure • Food control, precise amino acid ratio • Reduce runoff • Increase price of fertilizer

  6. Reducing Nitrogen Loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to Counter a Persistent Ecological Problem-Mitsch, et al. 2001

  7. Problems • Anthropogenic Additions of N to aquatic systems cause • Increased Productivity • Eutrophication • Hypoxia • Fish Kills

  8. Sources • Agriculture • Waste Water • Draining Wetlands

  9. Drained wetlands converted to agricultural land

  10. Solutions: Controlling N in Miss. River Basin • Modifying Agricultural Practice - use less fertilizer - apply fertilizer in spring - account for N sources present • Riparian and Wetland Buffers - effective nitrogen sinks due to high levels of denitrification

  11. Example of Riparian Buffer

  12. Solutions cont. • Urban & Suburban Non-point Source Control • Point Source Control • Controls on Atmospheric NOx • Mississippi River Diversions

  13. Creation of Wetlands

  14. Benefits of Reducing Nitrogen Levels in the Mississippi River Basin • Predicted 40% reduction of nitrogen loading to the Gulf through implementation of these practices • In addition to reduced hypoxia - reduced river pollution - reduced wetland loss - improved river ecosystems - improved control of floods

  15. Northeast U.S. Brief History • Population Changes • Land Use Changes • Capacity of 2nd Growth Forests for N-retention

  16. N-pollution Sources in Northeast U.S. (Driscoll et al. 2003) • Atmospheric N Sources • Food Imports • Fertilizer & Farming Practices • Feed Imports • Wastewater Effluent • Mycorrhizae & Legumes

  17. Problems • Acidic Deposition • Ground Level Ozone Formation • Coastal Eutrophication • Acidification & Overfertilization N-enrichment • Forest (N-saturation) • Freshwater (high flow) Smog in LA & Chicago

  18. Wet Deposition and Emissions a: nitrate, sulfate, b: nitrate & ammonium, c: sulfate, nitrate, chloride

  19. Ozone Formation • For Formation: NOx & VOC’s (volitile organic compounds) • Or NO from soil + Oxygen • VOC’s were thought to be limiting factor • Automobile VOC’s are regulated • VOC’s are also produced naturally (isoprene) • In Northeast U.S. we now believe that NOx regulates O3 formation • Ground Level O3 in many U.S. cities exceeds National Ambient Air Quality Standards

  20. Solution: Reductions in N Management Options: • Coastal Watersheds • Wastewater Treatment Plants • Agriculture • Atmosphere • Fossil fuel electric utilities • Transportation • Agriculture

  21. Purpose of Modeling • Models were run to test proposed management options and determine their effectiveness • Atmospheric Model: PnET-BGC • Estuary Loading: WATERSN

  22. Conclusions Estuary: Major N-source Wastewater effluent: Add biotic N-removal to wastewater treatment practices Atmosphere: Source Specific Control (due to numerous sources)

  23. Discussion Topics • Ecotechnology • Phytoremediation • Willow Project • Theoretical Models vs. Real Life Problems? • Lifestyle Changes • No Meat = No Nitrogen • SUV’s, Hybrids,Public Transportation, Walk, Bike • Other Effects of N • Purely Atmospheric take on N- Aerosols

  24. Willow Applications • Set-aside arable land • Bio-remediation of contaminated soils, like brownfields (phytoremediation) • Nutrient and waste management systems • Windbreaks/snow fences • Buffer zones for clean water Incorporating willow biomass crops into riparian buffers produces clean water and renewable energy (Salix Maskiner 2000)

  25. Soil Conservation • Very little soil erosion once the crop is established • Negligible N leaching from established willow plantings, even with large applications nitrogen (Adegbidi 1999, Aronsson et al. 2000). One year old coppcie growth

  26. Nitrogen Movement Trial with organic amendments with nitrogen loads ranging from 200 – 1,880 TKN kg/ha (Adeigbidi 1999)

  27. Aerosols What??? Aerosols absorb or scatter light Ecological Effect Photosynthesis GCEP 2004 Orientation Presentation by Jeff Gaffney

  28. The End

More Related