Comparing emissions from a cattle pen as measured by two micrometeorological techniques

Area of Science:

• Environmental Science
• Agricultural Engineering
• Atmospheric Chemistry

Background:

• Accurate measurement of ammonia (NH3) emissions from livestock facilities is crucial for environmental management.
• Micrometeorological techniques are often employed, but present unique challenges in complex environments like animal pens.

Purpose of the Study:

• To compare the efficacy of two micrometeorological techniques, Integrated Horizontal Flux (IHF) and Backward Lagrangian Stochastic (bLS), for measuring ammonia (NH3) emissions from a cattle pen.
• To assess the agreement between IHF and bLS methods under field conditions.

Main Methods:

• Utilized IHF and bLS techniques to measure NH3 emissions from an isolated 20m x 20m cattle pen over 29 days.
• Collected 124 paired 30-minute measurements under varying conditions.
• Applied a turbulent flux correction factor (TFcor) of 15% for the IHF method.

Main Results:

• No statistical difference was found between IHF and bLS ammonia emission measurements when TFcor was set to 15%.
• Both techniques, despite different sensor requirements and equipment layouts, yielded comparable results.
• The bLS technique offers simplicity and insensitivity to animal presence but has limitations in measurement continuity.

Conclusions:

• The IHF and bLS techniques provide equivalent ammonia emission data for cattle pens.
• The choice between IHF and bLS can be based on their respective advantages, such as IHF's near-continuous measurement capability and bLS's simplicity.
• This study validates the use of these micrometeorological methods for livestock emission monitoring.