Nitrous oxide flux observed with tall-tower eddy covariance over a heterogeneous rice cultivation landscape

Yanhong Xie; Mi Zhang; Wei Xiao; Jiayu Zhao; Wenjing Huang; Zhen Zhang; Yongbo Hu; Zhihao Qin; Lei Jia; Yini Pu; Haoran Chu; Jiao Wang; Jie Shi; Shoudong Liu; Xuhui Lee

doi:10.1016/j.scitotenv.2021.152210

Nitrous oxide flux observed with tall-tower eddy covariance over a heterogeneous rice cultivation landscape

Sci Total Environ. 2022 Mar 1:810:152210. doi: 10.1016/j.scitotenv.2021.152210. Epub 2021 Dec 8.

Authors

Yanhong Xie¹, Mi Zhang², Wei Xiao², Jiayu Zhao¹, Wenjing Huang¹, Zhen Zhang³, Yongbo Hu¹, Zhihao Qin¹, Lei Jia¹, Yini Pu¹, Haoran Chu¹, Jiao Wang⁴, Jie Shi¹, Shoudong Liu¹, Xuhui Lee⁵

Affiliations

¹ Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China.
² Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China; Key Laboratory of Meteorological Disaster, Ministry of Education and Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China.
³ Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China; Nanjing Jiangning District Meteorological Bureau, Nanjing, Jiangsu Province, China.
⁴ Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change (ILCEC), Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China; Taiyuan Meteorological Bureau, Taiyuan, Shanxi Province, China.
⁵ School of the Environment, Yale University, New Haven, CT, USA. Electronic address: xuhui.lee@yale.edu.

PMID: 34890681
DOI: 10.1016/j.scitotenv.2021.152210

Abstract

Although croplands are known to be strong sources of anthropogenic N₂O, large uncertainties still exist regarding their emission factors, that is, the proportion of N in fertilizer application that escapes to the atmosphere as N₂O. In this study, we report the results of an experiment on the N₂O flux in a landscape dominated by rice cultivation in the Yangtze River Delta, China. The observation was made with a closed-path eddy covariance system on a 70-m tall tower from October 2018 to December 2020 (27 months). Temperature and precipitation explained 78% of the seasonal and interannual variability in the observed N₂O flux. The growing season (May to October) mean flux (1.14 nmol m^-2 s^-1) was much higher than the median flux found in the literature for rice paddies. The mean N₂O flux during the observational period was 0.90 ± 0.71 nmol m^-2 s^-1, and the annual cumulative N₂O emission was 7.6 and 9.1 kg N₂O-N ha^-1 during 2019 and 2020, respectively. The corresponding landscape emission factor was 3.8% and 4.6%, respectively, which were much higher than the IPCC default direct (0.3%) and indirect emission factors (0.75%) for rice paddies.

Keywords: Eddy covariance; Emission factor; Heterogeneous rice cultivation landscape; N(2)O flux.

MeSH terms

Agriculture
Air Pollutants* / analysis
China
Environmental Monitoring
Fertilizers / analysis
Nitrous Oxide / analysis
Oryza*
Soil

Substances

Air Pollutants
Fertilizers
Soil
Nitrous Oxide