Rubisco is about 20% of the plant protein and is argued to be the most abundant protein on Earth (Sharkey, 1985). This Explain why N compounds

Rubisco is about 20% of the plant protein and is argued to be the most abundant protein on Earth (Sharkey, 1985). This Explain why N compounds released when organic matter is combusted. 2

TRY database, Kattge et al. Global Change Biology 3

Field and Mooney 1986 4

From Reich et al 5

Here is a case showing good relations between reflectance and canopy nitrogen. This relation has UTILITY. Yet, it has received much criticism from remote sensing experts. Cons,,critics claim it is an artifact. When the bidirectional reflectance is corrected for canopy structure there becomes a negative relation between N and reflectance and they claim the observations conflict with the physics of leaf reflectance in a 3D canopy and how those photons emerge from the canopy Pros see townsend 6

Decomposition, Mineralization and Ammonification are essentially equivalent. All of these processes are mediated by microbes. Some paths are aerobic. Others are Anaerobic 8

Immobilization is the conversion of inorganic N to organic form by microbes. As such it is inavailable top plants until the microbes die and decompose. 9

Popular theory produced by Berkeley professor Mary Firestone. N2O is emitted at several steps in the nitrification and denitrification processes, which are mediated by microbes. Nitrification tends to occur by aerobic microbes. Denitrification occurs by different microbes working in anaerobic conditions. 13

N loading on the biosphere can lead to gaseous loss of N compounds through nitrification and denitrification. N2O leads to greenhouse warming and loss of ozone in the stratosphere. NOx leads to ozone pollution and aerosols and lower visibility and human health issues 14

Pilegaard 2013 Phil Trans Roy Soc B 15

http://1.bp.blogspot.com/ 0u6e08xdYi8/U35Ie64th0I/AAAAAAAAC0Q/u6bO5FCu_Q/s1600/plant_fixing_nitrogen_large.jpg N2 is converted to ammonium, NH4+ by symbiosis with nitrogen fixing prokaryotes (bacteria and archaea), diazotrophs 16

Fowler et al 2013 18

BNF, Biological Nitrogen Fixation Fowler et al 2013 Phil Trans Roy Soc B http://d1vn86fw4xmcz1.cloudfront.net/content/royptb/368/1621/20130164/f1.large.j pg?width=800&height=600&carousel=1 20

Tg = 10^12 g 21

There are a number of nitrogen compounds in the air 23

Key processes involve Wet and Dry Deposition, Leaching and Lateral Transport, losses include Biomass Burning, Fossil fuel Combustion, Denitrification 25

Pilegaard 2013 Phil Trans Roy Soc B 27

http://www.physicalgeography.net/fundamentals/images/acid_deposition.jpg 29

http://www.atdd.noaa.gov/?q=node/46 30

Streets et al 2013 Atmos Environment. Good news on the Nox front across Europe and North America. Clean air act and emissions controls are working Satellite observations from Space. Europe GOME and Schiamachy satellites. US MODIS and MOPPITT, OMI 37

Ammonia sources and sinks revolve around agriculture 40

Example of ammonia budget 43

Nitrogen compounds inter relate with one another and have multiple effects on the environments, both good and bad. Ammonium and nitrate are plant nutrients, fertilizers. But if there is too much produced they can have deliterious effects on the environment including greenhouse gas warming, pollution, ozone depletion, acid rain, and eutrophication or dead zones in lakes and the ocean 45

Laughing gas. It is a strong greenhouse gas, it is generally non reactive in the tropophere, so it can diffuse up to the stratosphere and participate in ozone depleting reactions where it is cold and uv light is abundant to produce O singlet D molecules that destroy N2O and produce NO, which directly destroys ozone. 46

http://www.coe.ou.edu/sserg/web/results/results.htm from HITRAN absorption spectra.. Nitrous oxide has a greenhouse warming potential about 298 times that CO2 for a 100 year time frame. It has a lifetime of about 114 years. 47

There has been marked increases in N2O following the development of fertilizers after World War II and the expansion of agriculture to support growing populations with the industrial revolution. Mid 19 th Century N2O concentrations were on the order of 275 ppb. Today, N2O concentrations exceed 310 ppb 48

http://www3.epa.gov/climatechange/science/indicators/ghg/ghg concentrations.html 49

http://d1vn86fw4xmcz1.cloudfront.net/content/royptb/368/1621/20130164/f3.large.j pg 52

fowler 53

Can we rely on Organic Farming to Fix Enough N to feed the Worlds Population? 54

Fowler 57

Gruber and Galloway, 2008 Nature, http://www.nature.com/nature/journal/v451/n7176/images/nature06592 f3.2.jpg 58

http://toxics.usgs.gov/definitions/eutrophication.html 60

http://www.gulfhypoxia.net/overview/images/image005.png 61

Http://www.globalchange.umich.edu/gctext/Inquiries/Inquiries_by_Unit/Unit_10.htm N run off from fertilizer applied to farms in the Mississippi River basin flow out to the Gulf. These stimulate an algal bloom. Decomposition of dead algal cells consumes oxygen, which becomes depleted and stress sea life 62

http://www.gulfhypoxia.net/overview/images/image001.png 63

http://newswatch.nationalgeographic.com/files/2014/04/gulf_of_mexico_hypoxiazone _NOAA highres.jpg 64

Runoff of nitrogen compounds is causing hypoxia in the Gulf of Mexico 65

http://www.ncddc.noaa.gov/approved_recs/ncddc_ims/gis/ims/final/2015contours_br owse_2015 contours.jpg 66

http://service.ncddc.noaa.gov/rdn/www/media/hypoxia/maps/ldwf2015.jpg 67

http://toxics.usgs.gov/hypoxia/images/hypoxic_zone_graph.gif Data source: N.N. Rabalais, Louisiana Universities Marine Consortium, R.E. Turner, Louisiana State University Funded by: NOAA, Center for Sponsored Coastal Research 68

Typical global budgets for N2O 73