**Farm, Ranch, and Rural** 

**Communities Meeting**  **Wa shington**  **DC February**  **23, 2009** 

# Integrated **Nitrogen Management** 

**James N. Gallow ay**  **Univ ersity**  **of V irginia**  **Thomas L. Theis Univ** **ersity of Illinois at Chicago** 

**for the Integrated Nitrogen Committee** 

**of the USEP**  **A Science**  **Ad visory**  **Board**12/17/2013 2 

# Integrated Nitrogen Committee

• **A self -**  **initiated project of the Science Advisory** **B oard**  **begun 1/2007, projected completion 9/2009**
• **Cross representation from universities, industries, government, and NGOs** 
• **Based on the need to develop better strategies to manage Nr** 
• **Draft report: http://y**  **osemite.epa.gov/sab/sabproduct.nsf/Meeting Cal/F5B0375541B31DB78525753800486151?OpenDo**  **cument.**
• **Comments welcome through M arch**  **1**

# Overview **of Talk**  

# Reactive Nitrogen **(Nr) and the N Cascade**   

# Sources of Nr in the US.  

# Nr Fate in the US.  

# Consequences, **Impacts and Metrics.**  

# Selected Recommendations12/17/2013 4 

# What is Reactive Nitrogen? All chemical forms of nitrogen, except N 2 

# Examples: NH 3 

# - NH 4 + 

# , N 2 

# O, NO, NO2, NO 2 - 

# , NO 3 - 

# Organic - N12/17/2013 5 

# Why do we need reactive nitrogen?

• **Human dietary Nr requirement**  **= 4.3 kg/cap/yr** • **US = 1.4 Tg/yr** • **World = 28 Tg/yr**

# Nr Introduction into the US

 **Fossil fuel combustion**  

# stationary**sources**  

# transportation sources  **Haber Bosch Nr**  

# produced in US  

# imported from other countries  **Import of N**  **- containing commodities**   

# grain and meat  **Biological nitrogen fixation (BNF)**   

# managed lands  

# unmanaged lands

# The Nitrogen Cascade  The concept of the nitrogen cascade emphasizes that once a new Nr molecule is created, it can be sequentially transformed and travel throughout the environment and contribute to a series of major environmental problems.12/17/2013 8 

### The Nitrogen Cascade **Atmospheric Terrestrial**  **Agricultural**

animals crops soils **Vegetated** grasslands forests soils

Gro undwater 

### Aquatic Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y**  **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification**12/17/2013 9



# Overview **of Talk**  

# Reactive Nitrogen **(Nr) and**  **the Nr Cascade**  

# Sources of Nr in the US.  

# Nr Fate in the US.  

# Consequences, **Impacts and Metrics.**  

# Selected Recommendations

# Nr Introduction into the US **Tg N/y r**  **3. 5**  **1. 9**  **7. 7**  **10. 9**  **4.2 6.**  **4** 

## Natural BNF

### 3. **5 1.**  **9 7.**  **7 10.**  **9 4.2**  **6. 4**  

## NOx transportation Natural BNF 

# Nr **Introduction into the US** 

**Tg N/yr**

### 3. **5 1.**  **9 7.**  **7 10.**  **9 4.2**  **6. 4**  

## NOx transportation NOx stationary Natural BNF 

# Nr **Introduction into the US** 

**Tg N/yr**

### 3. **5 1.**  **9 7.**  **7 10.**  **9 4.2**  **6. 4**  

## NOx transportation NOx stationary Cultivation BNF Natural BNF 

# Nr **Introduction into the US** 

**Tg N/yr**

### 3. **5 1.**  **9 7.**  **7 10.**  **9 4.2**  **6. 4**  

## NOx transportation NOx stationary Cultiv ation BNF
HB - N Fertilizer Natural BNF 

# Nr **Introduction into the US** 

**Tg N/yr**

### 3. **5 1.**  **9 7.**  **7 10.**  **9 4.2**  **6. 4**  

## NOx transportation NOx stationary Cultiv ation BNF
HB - N F ertilizer HB - N Industry Natural BNF

**Natural, 6.5 Tg N/y**  **r Anthropogenic,**  **29 Tg Nr/y r**  

# Nr **Introduction into the US** 

**Tg N/yr**12/17/2013 16



# Overview **of Talk**  

# Reactive Nitrogen **(Nr) and**  **the Nr Cascade**  

# Sources of Nr in the US.  

# Nr Fate in the US.  

# Consequences, **Impacts and Metrics.**  

# Selected Recommendations

# Fate of Introduced **Nr**  **Lost as Nr from US**  

# via rivers  

# via atmospheric **advection**  

# via exports  **Stored as Nr**  

# in soils & vegetation  

# In groundwater  **Denitrified to N 2** 

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **Import, 6.0**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  

### N **2** 

### O 

# US Nitrogen Budget

**Tg N y r**  **- 1** 

# US Nitrogen Budget **Tg N y r**  **- 1**  

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **3.1 2.7**  **0.8**

**Import, 6.0**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  **2.1** 

### N **2** 

### O **0.8**

# US Nitrogen Budget **Tg N y r**  **- 1**  

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **3.1 2.7**  **0.8**

**Import, 6.0**  **Export, 4.3**  **Atm advection, 4.6**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  **2.1** 

### N **2** 

### O **0.8 Atm advection,**  **0.8**

**River, 4.8** 

# US Nitrogen Budget **Tg N y r**  **- 1**  

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **3.1 2.7**  **0.8**

**Import, 6.0**  **Export, 4.3**  **Atm advection, 4.6**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  **2.1** 

### N **2** 

### O **0.8 Atm advection,**  **0.8**

**River, 4.8**  **Nr Inputs: 35 Tg**  **N Nr Outputs:**  **14 Tg N**  **Nr Missing: 21 Tg**  **N**

# US Nitrogen Budget **Tg N y r**  **- 1**  

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **3.1 2.7**  **0.8**

**Import, 6.0**  **Export, 4.3**  **Atm advection, 4.6**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  **2.1** 

### N **2** 

### O **0.8 Atm advection,**  **0.8**

**River, 4.8**  **Nr Inputs: 35 Tg**  **N Nr Outputs:**  **14 Tg N**  **Nr Missing: 21 Tg**  **N Nr Storage: 5 Tg N**  **~ 2 Tg soils&vegetation ~ 3 Tg groundwater** 

# US Nitrogen Budget **Tg N y r**  **- 1**  

### N **2** 

### NO **y** 

### NH **x**
**C -**  **BNF, 7.7**  **Fert. prod., 9.4**  

### United States **3.1 2.7**  **0.8**

**Import, 6.0**  **Export, 4.3**  **Atm advection, 4.6**  **Lightning, 0.1**  **Fossil fuel, 5.4**  **BNF, 6.4**  **2.1** 

### N **2** 

### O **0.8 Atm advection,**  **0.8**

**River, 4.8**  **Nr Inputs: 35 Tg**  **N Nr Outputs:**  **14 Tg N**  **Nr Missing: 21 Tg**  **N Nr Storage: 5 Tg N**  **~ 2 Tg soils&vegetation ~ 3 Tg groundwater**  **Nr Denitrified to N**  **2 :**  **21 Tg N**  **- 5 Tg**  **N = 16 Tg**  **N**12/17/2013 24



# Overview **of Talk**  

# Reactive Nitrogen **(Nr) and**  **the Nr Cascade**  

# Sources of Nr in the US.  

# Nr Fate in the US.  

# Consequences, **Impacts and Metrics.**  

# Selected Recommendations12/17/2013 25 

# Impacts of manufactured Nr Positive Protein requirements for ~3 billion humans Fertilization of forests Negative Air quality impairment Eutrophication/hypoxia Loss of biodiversity Global warming Acid rain Ozone depletion Drinking water contamination12/17/2013 26 

# Major (US) federal laws for **managing nitrogen** • **CAA (1990) regulates NO**  **x** 

# emitted into **atmospheric sy** **stems**
• **CWA (1977) regulates NH**  **3** 

# and **total Nr released into aquatic**  **sy stems** 
• **SDWA (1996) regulates NO**  **3 -**  

# and NO **2 -**  

# in **potable waters** 
• **EISA (2007) requires the setting of biofuel**  **standards based**  **on life cy cle** 12/17/2013 27



# Metrics for Nr **Quantity: Mass, concentration,**  **flux, loading Impacts:**  **Category a**  **nd ecosy stem**  **services Policy** **: Adverse**  **risk Economic**  **: Price of benefits**  **and costs Regulatory:**  **Criteria, Standards**  **& Thresholds**12/17/2013 28 

# Metrics Case Study **: Chesapeake**  **Bay**

Image from Chesapeake Bay F oundation12/17/2013 2912/17/2013 30 

# Share of Nitrogen **(Mass) to the Chesapeake Bay** 

**Wa tershed**  **by S**  **ource S**  **h a** **r e**  **o f**  **N i** **t r**  **o g** **e n**  **S o**  **u r** **c**

**e s**  **i n**  **t h** **e C**  **h e**  **s a** **p e**  **a k** 

**e B** **a y**  **W a**  **t e**  **r s**  **h e**  **d A**  **c c**  **o r**  **d i**  **n g**  **t o**  **D i** **f**

**f e**  **r e**  **n t**  **M e**  **t r**  **i c** 

**s**

0% 20% 40% 60% 80% 1 00%

T

on n e s N M

i l l i on $ D am age M

or tal ity M

it i ga t i on $ / T on ne F r

es hw a t e r E m i s s i o ns T err es t ri a l E m i s s i on s A t mo s p h e r i c E m i s s i o ns

Modified from Moomaw and Birch, 200512/17/2013 31 

# Nr to Chesapeake Using Different Metrics **Sha re**  **of N itr**  **oge n S**  **our ce**  **s in the C**  **he sap**  **ea ke**  **B ay**  **W at**  **er sh**  **ed Ac**  **co rd**  **ing to D iffe**  **re nt** **M et**  **ri cs** 

0% 20% 40% 60% 80% 100%

To nnes N Mi llio n $ Da ma ge Mo rt al ity Mi ti gati on $/T onne Fr

es hwat er Em is si ons Te rres tria l Emis si ons Atmo sp heri c Em is si ons12/17/2013 32



# Overview **of Talk**  

# Reactive Nitrogen **(Nr) and the Nr Cascade**   

# Sources of Nr in the US.  

# Nr Fate in the US.  

# Consequences, **Impacts and Metrics.**  

# Selected Recommendations

# Control **Points**  **The overarching objective is to maintain the**  **benefits of nitrogen while minimizing the**  **losses to the environment.**  **Control points are locations**  **in the N cascade where:**   

# N uptake processes **can be improved**  

## e.g., nitrogen use efficiency  

# N losses to environment can be better managed  

## e.g., **wa ste** **water**12/17/2013 34 

# Selected Recommendations  **INC makes the following five**  **recommended actions at control points**  **These recommendations, if enacted,**  **would reduce the anthropogenic**  **Nr load to the US environment**  **by 20% The Nitrogen Cascade**  **Atmospheric Terrestrial**  **Agricultural**

animals crops soils **Vegetated** grasslands forests soils

Groundwater **Aquatic** Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y** **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification** 

# Control Point: **Combustion**

**Current: 5.4 Tg N**  **Proposed: 3.4 Tg N**  **Reduction: 2 Tg N** 

• **We recommend that the EPA expand**  **its NOx control efforts**  **to include 90% decreases**  **of emissions from heavy**  **- duty on**  **- road,**  **all off**  **- road**  **mobile sources**  **and currently uncontrolled electricity**  **generation and industrial**  **processes. The Nitrogen Cascade**  **Atmospheric Terrestrial**  **Agricultural**

animals crops soils **Vegetated** grasslands forests soils

Groundwater **Aquatic** Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y** **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification** 

# Control Point: **NH 3**  

# from Manure and Fertilizer

**Current: 2.7 Tg N**  **Proposed: 2.0 Tg N**  **Reduction 0.7 Tg N** 

• **We recommend decreasing**  **livestock -**  **derived ammonia**  **emissions to approximately**  **80% of 1990 emissions, a decrease**  **of 0.5 Tg N per**  **year.** • **We recommend decreasing**  **ammonia emissions derived**  **from fertilizer**  **applications by 20%, a decrease**  **by ~0.2 Tg N per year. The Nitrogen Cascade**  **Atmospheric Terrestrial**  **Agricultural**

animals crops soils **Vegetated** grasslands forests soils

Groundwater **Aquatic** Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y** **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification** 

# Control Point: **Nr losses from Croplands**

**Current: 4.8 Tg N**  **Proposed: 3.8 Tg N**  **Reduction 1.0 Tg N** 

• **We recommend decreasing**  **flows of Nr into streams, rivers,**  **and coastal**  **systems by approximately 20% through improved**  **landscape management, including**  **wetland management improved**  **tile -**  **drainage systems and riparian**  **buffers on crop**  **land, etc.** **The Nitrogen Cascade Atmospheric**  **Terrestrial Agricultural** 

animals crops soils **Vegetated** grasslands forests soils

Groundwater **Aquatic** Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y** **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification** 

# Control Point: **Nitrogen Use Efficiency**

**Current: 18.6 Tg N**  **Proposed: 16.2 Tg N**  **Reduction 2.4 Tg N** 

• **We recommend an increase**  **in crop N**  **- uptake efficiencies**  **of 25% over**  **current levels through a combination**  **of knowledge -**  **based practices**  **and advances in fertilizer**  **technology (such as controlled**  **release). The Nitrogen Cascade**  **Atmospheric Terrestrial**  **Agricultural**

animals crops soils **Vegetated** grasslands forests soils

Groundwater **Aquatic** Surface Water & Wetlands Coastal Bays

& Estuaries Oceans **NO y**  **, NH**  **x , N**  **org**
**NO x**  **NH 3,**  **N org** 

**NO y** **, NH**  **x , N**  **org N**  **2 O** 

**Populated** landscape people soils **biogeochemical cycling greenhouse gases** 

**eutrophication ecosystem productivity** 

denitrification potential **N 2**  **O** troposphere stratosphere

**NO y ,**  **NH x**  **N org**  **ozone Food Production**  & creation of synthetic fertilizers **Energy Production** & combustion of fossil fuels **Ò new**  **Ó nitrogen**  **NH x** 

**NO x**  **ozone depletion particulate matter** 

**acidification** 

# Control Point: **Wa stew**  **ater T reatment** 

**Current: 1.9 Tg N**  **Proposed: 1.1**  **- 1.4 Tg N**  **Reduction 0.5**  **- 0.8 Tg N** 

• **We recommends that a high priority**  **be assigned to nutrient**  **management through a targeted construction grants program**  **for improved**  **wastewater treatment under**  **the CWA**

# Integrated Nitrogen Committee

**Summary of Findings**  **Human action controls Nr introduction into the US.**   **Added Nr has positive impacts for human health --**  **food production.**  **Added Nr increases the risk to both human and ecosy** **stem health**  **-- N cascade.**   **Challenge is how d**  **o w e**  **achieve positive benefits at acceptable risk.**   **And how d**  **o w e**  **do this in an integrated fashion?**