AUTHOR=Xu Xiangyu , Zhang Minmin , Xiong Yousheng , Shaaban Muhammad , Yuan Jiafu , Hu Ronggui 

TITLE=Comparison of N2O Emissions From Cold Waterlogged and Normal Paddy Fields

JOURNAL=Frontiers in Environmental Science

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2021.660133

DOI=10.3389/fenvs.2021.660133

ISSN=2296-665X

ABSTRACT=<p>Paddy fields are major sources of atmospheric N<sub>2</sub>O. Soil temperature and moisture strongly affect N<sub>2</sub>O emissions from rice fields. However, N<sub>2</sub>O emissions from cold-waterlogged paddy fields (CW), an important kind of paddy soil in China, are not well studied so far. It is unclear whether the N<sub>2</sub>O emissions from cold-waterlogged paddy fields are the same as normal paddy fields (NW). We investigated the N<sub>2</sub>O emission characteristics from the CW and NW paddy fields under with (R<sub>1</sub>) and without (R<sub>0</sub>) rice in Tuku Village, Baisha Town, Yangxin County (YX site, monitoring in 2013) and Huandiqiao Town, Daye City (DY site, monitoring in 2014); compared the difference and influencing factors between the CW and NW paddy fields at two sites in South China. The results showed that the N<sub>2</sub>O emissions from NWR<sub>0</sub> were 13.4 times higher than from CWR<sub>0</sub>, and from NWR<sub>1</sub> were 10.3 times higher than from CWR<sub>1</sub> in the YX site. The N<sub>2</sub>O emissions from NWR<sub>0</sub> were 2.4 times higher than from CWR<sub>0</sub>, and from NWR<sub>1</sub> were 17.3 times higher than from CWR<sub>1</sub> in the DY site. The structural equation models (SEMs) showed that the N<sub>2</sub>O emissions are mainly driven by rice planting and soil moisture in the NW fields at the annual scale, while soil temperature in the CW fields. Overall, N<sub>2</sub>O emissions from cold waterlogged paddy fields are significantly lower than those of normal paddy fields due to the low temperature and higher water content; however, there are dinitrogen emissions from cold waterlogged paddy fields denitrification should be further examined.</p>