ATMOSPHERIC DEPOSITION OF NH3 GAS: RELATION TO WATER QUALITY IN THE SUSQUEHANNA RIVER BASIN AND TO INPUTS TO AGRICULTURAL SYSTEMS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0212152
• Project Start Date: Oct 1, 2007
• Project End Date: Sep 30, 2010
• Program Code: [(N/A)]- (N/A)

Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853

Performing Department
ECOLOGY & EVOLUTIONARY BIOLOGY

Non Technical Summary
Large quantities of ammonia gas are emitted to the atmosphere from animal farming operations. When this ammonia is deposited back onto the ground, it can contribute to the nitrogen economy of agricultural fields but also can result in downstream water quality nitrogen pollution. This project will measure the rate of this ammonia gas deposition in the watersheds of the Susquehanna River basin in New York, a major tributary of Chesapeake Bay.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
112	0399	1070	50%
112	0410	1070	25%
112	0210	2050	25%

Knowledge Area
112 - Watershed Protection and Management;

Subject Of Investigation
0210 - Water resources; 0399 - Watersheds and river basins, general; 0410 - Air;

Field Of Science
2050 - Hydrology; 1070 - Ecology;

Keywords

nitrogen

nitrogen pollution

ammonia

ammonia deposition

susquehanna river

atmospheric deposition

nitrogen deposition

Goals / Objectives
Large amounts of ammonia gas are emitted to the atmosphere from manure and from other animal wastes. The fate of this ammonia is very poorly known. Some returns to the ground as ammonium (NH4+, the ionic form of ammonia gas) in wet deposition (rain and snow), but ammonia gas is extremely reactive, and much is probably deposited onto the landscape as the gas interacts with vegetation. Some of this may deposit very close to the site of emission: within meters to hundreds of meters to a kilometer or so. This deposited ammonia gas contributes to the nitrogen pollution to forests and other natural ecosystems, potentially affecting the forest but also contributing to downstream water pollution. Some of the ammonia volatilized from animal wastes also contributes as a nitrogen input to adjacent agricultural fields, acting as fertilizer. We propose to use passive ammonia gas samplers to measure ammonia concentrations along gradients away from agricultural emission sources. From these data, we can estimate the magnitude and spatial extent of dry ammonia gas deposition. We will also measure through fall at a subset of sites in forested areas to obtain a measure of total nitrogen deposition with which to compare the gas deposition estimates.

Project Methods
We will measure concentrations of ammonia gas in the air along transects away from dairy farms using Ogawa passive gas samplers. The transects will extend up to 10 km away, using a geometric progression with tighter spacing of sites closer to the source of ammonia emissions (i.e., samplers at 10 m, 25 m, 60 m, 150 m, 500 m, 3 km, and 10 km); we will run transects in several directions from the farms so as to determine the influence of prevailing winds. Additionally, we will place samplers in agricultural fields in order to assess the input of nitrogen from dry gaseous ammonia deposition to those fields. We will deploy the passive samplers for periods of 2-3 weeks at a time for four different times during the year (once each season). Rates of dry deposition of ammonia gas will be estimated from the concentration data and from appropriate depositional velocities. At some of our sites along the transects away from farms, we also will measure through fall as an estimate of total nitrogen deposition with which to compare the estimates for dry ammonia gas deposition at those same sites. We will use event-based sampling at a subset of our forested sites during seasons when leaves are present on the trees.

Progress 10/01/07 to 09/30/10

Outputs
OUTPUTS: We have measured concentrations of ammonia gas in the atmosphere at various distances (0 m to 5 km) away from a large dairy farm operation a total of 6 times, every 2 to 3 months. Surveys were conducted in each of the four seasons. Our goal was to determine the fate of ammonia volatilized to the atmosphere from the farming operations, with an emphasis on estimating how much of this is re-deposited back onto the landscape in the near vicinity of the farm. We found that air concentrations of ammonia fall off substantially within 500 to 1,200 m of a concentrated source (dairy barn, medium class CAFO). Within 500 m of the source area, ammonia concentrations almost always exceed 4 micrograms per cubic meter and were as high as 15 mcg per cubic meter. These levels exceed the European Air Quality Standard of 1 to 4 mcg per cubic meter for acid-sensitive and all other environments, respectively. While ammonia air concentrations are not currently regulated in the U.S., this is under consideration. Ammonia gas concentrations differ seasonally (higher in the warmer months) but the spatial pattern is quite consistent. Air concentrations in agricultural fields were similar to the highest concentrations found in the source area, and concentrations in the forested "background" sites were at or below 0.5 mcg per cubic meter. PARTICIPANTS: Thomas Butler (Cornell and Cary Institute of Ecosystem Studies), Marina Molodovskaya (Cornell, now at University of British Columbia). TARGET AUDIENCES: New York State DEC; manuscript in preparation for publication in peer-reviewed journal. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This is the final year of this small, exploratory project. The results of this research are being used to inform the TMDL (Total Maximum Daily Load) process for Chesapeake Bay by the NY State DEC.

Publications

• No publications reported this period

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: During the past year, we have been measuring concentrations of ammonia gas in the atmosphere at various distances (0 m to 5 km) away from a large dairy farm operation. Surveys were conducted in each of the four seasons, using passive samplers to measure the concentrations. Our goal is to determine the fate of ammonia volatilized to the atmosphere from the farming operations, with an emphasis on estimating how much of this is re-deposited back onto the landscape in the near vicinity of the farm. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This is the second year of this small, exploratory project. Outcomes include the following publication.

Publications

• Entringer, R. and R.W. Howarth. 2009. Workshop on Atmospheric Deposition of Nitrogen -- Chesapeake Bay Program Science and Technical Advisory Committee. January 8, 2009. STAC Publication 09-001. http://www.chesapeake.org/stac/Pubs/atmosphericnitrogen.report.pdf

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: During the past year, we began measuring concentrations of ammonia gas in the atmosphere at various distances (0 m to 5 km) away from a large dairy farm operation. Surveys were conducted in each of the four seasons, using passive samplers to measure the concentrations. Our goal is to determine the fate of ammonia volatilized to the atmosphere from the farming operations, with an emphasis on estimating how much of this is re-deposited back onto the landscape in the near vicinity of the farm. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This is the first year of this small, exploratory project. We do not yet have outcomes or impacts to report.

Publications

• Howarth, R. W. 2008. How important is atmospheric deposition as a source of nitrogen to coastal marine ecosystems in the northeastern United States? Pages 47-65 in A. Desbonnet and B. A. Cost-Pierce (eds.), Science of Ecosystem-Based Management. Springer, New York.