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Reduced methane and nitrous oxide emissions from ratoon rice paddy in Chaohu polder area, China |
Received:February 16, 2021 |
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KeyWord:ratoon rice;rice-wheat rotation;greenhouse gas emission;Chaohu polder |
Author Name | Affiliation | E-mail | WANG Tianyu | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China University of Chinese Academy of Sciences, Beijing 100049, China | | FAN Di | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China University of Chinese Academy of Sciences, Beijing 100049, China | | SONG Kaifu | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China University of Chinese Academy of Sciences, Beijing 100049, China | | ZHANG Guangbin | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China | | XU Hua | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China | | MA Jing | State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China | jma@issas.ac.cn |
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Abstract: |
A field experiment was conducted from 2019 to 2020 to compare the differences in methane(CH4) and nitrous oxide(N2O) emissions between ratoon rice(RR) fields and rice-wheat rotation(SW) fields in Chaohu polder using the static chamber-gas chromatograph technique. CH4 and N2O fluxes from the RR and SW fields were observed, while the soil redox potential(Eh), soil dissolved organic carbon(DOC), soil ammonium(NH4+-N), and soil nitrate(NO3--N) contents were determined during the rice-growing season. The study results revealed that larger CH4 flux peaks appeared in the SW treatment during the rice greening and tillering stages. However, CH4 flux peaks of the RR treatment appeared at the regreening and tilling stages in the main season, and at the ripening stage of the main season, and in the first half of the ratoon season. The N2O flux peaks of the SW treatment primarily appeared after precipitation in the wheat season and during drainage periods, while N2O flux peaks for the RR treatment mainly appeared after fertilizer application for bud promotion. Compared with SW, the annual total CH4 emissions, total N2O emissions, total greenhouse gas emissions, and greenhouse gas emission intensities of RR were reduced by 22.3%, 86.5%, 36.3%, and 15.9%, respectively(P<0.05). No wheat grain was produced in the RR treatment, and rice yield increased by 16.2%(P<0.05). The seasonal variation in CH4 flux during the rice-growing season for each treatment was significantly negatively correlated with soil Eh(P<0.01), but no significant correlation was found between CH4 flux and soil DOC concentration(P>0.05). The seasonal variation of N2O flux for RR treatment during the rice-growing season was significantly positively correlated with soil NH4+-N content(P<0.05). In conclusion, planting ratooning rice in the Chaohu polder area increases rice yield and dramatically reduces the comprehensive greenhouse effect and greenhouse gas emission intensity. |
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