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09:03
Assessment of Methane and Nitrous Oxide Fluxes from Paddy Field by Means of Static Closed Chambers Maintaining Plants Within Headspace
Published on: September 6, 2018
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Ammonia emissions from paddy fields are underestimated in China
Hongyuan Wang1, Dan Zhang1, Yitao Zhang1
1Key Laboratory of Nonpoint Source Pollution Control, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Environmental Pollution (Barking, Essex : 1987)
|January 12, 2018
Summary
Ammonia (NH3) emissions from Chinese paddy fields are higher than previously estimated, accounting for 17.7% of applied nitrogen. Fertilizer application rates significantly impact these emissions, highlighting the need for air quality considerations in agricultural pollution control.
Area of Science:
- Agricultural Science
- Environmental Science
- Atmospheric Chemistry
Background:
- Excessive nitrogen fertilizer use in China leads to significant ammonia (NH3) loss from agricultural lands.
- Quantifying NH3 emissions from paddy fields is challenging due to methodological variations and climatic factors, resulting in large uncertainties.
Purpose of the Study:
- To accurately measure and quantify ammonia (NH3) emissions from typical Chinese rice cropping systems.
- To identify key factors influencing NH3 emission rates and to estimate total NH3 emissions from paddy fields in China.
Main Methods:
- Standardized measurement methods were employed over two years across three distinct rice cropping systems in China.
- A total of 3131 observations were collected to analyze NH3 emissions in relation to nitrogen application rates and environmental factors.
Main Results:
- Ammonia (NH3) emissions represented 17.7% of applied nitrogen, a figure 33.1% higher than prior estimates.
- Nitrogen application rate was identified as the primary driver of NH3 emission rates, showing an exponential increase with fertilizer application.
- Estimated total NH3 emissions from Chinese paddy fields reached 1.7 Tg N yr-1 in 2013, exceeding N losses via water pathways.
Conclusions:
- Current agricultural practices result in substantial ammonia (NH3) loss to the atmosphere from paddy fields in China.
- Mitigation strategies for agricultural non-point source pollution must address both water and air emissions to effectively improve environmental quality and air quality.
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