Cutting-edge ammonia emissions monitoring technology for sustainable livestock and poultry breeding: A comprehensive review of the state of the art

Accurately monitoring ammonia emissions from the most important contributor, i.e., livestock and poultry breeding sources, is crucial for assessing total emissions, understanding the mechanism behind ammonia-related environmental issues, and promoting sustainable agriculture practices. However, developing field-based methods to monitor ammonia emissions in complex and fluctuating environments has always been a significant challenge, hindering the establishment of an accurate ammonia emission profile, necessary for decision-makers to tailor solutions to guide sustainable agricultural practices. This review thus systematically summarizes recent advancements in ammonia emission monitoring technologies for livestock and poultry breeding sources, encompassing three self-classified techniques, including chemical instrument-based, spectroscopy-based, and sensor-based methods. The review also provides a comparative analysis and discussion of their technical principles, technical characteristics (e.g., sensitivity, accuracy, detection range and response time, etc.), application scenarios, and scope. Furthermore, this work introduces microfluidics and membrane technologies that can subtly be integrated with sensor-based technology to address gaps in existing monitoring technologies, elaborating their feasibility and application potential in detail for monitoring ammonia emissions from livestock and poultry sources. These insights illuminate future trends in the development of field-based, real-time ammonia emission monitoring technology for sustainable agriculture.