Clay-hydrochar composites mitigated CH4 and N2O emissions from paddy soil: A whole rice growth period investigation

Detian Li; Huiting Li; Danyan Chen; Lihong Xue; Huayong He; Yanfang Feng; Yang Ji; Linzhang Yang; Qingnan Chu

doi:10.1016/j.scitotenv.2021.146532

Clay-hydrochar composites mitigated CH₄ and N₂O emissions from paddy soil: A whole rice growth period investigation

Sci Total Environ. 2021 Aug 1:780:146532. doi: 10.1016/j.scitotenv.2021.146532. Epub 2021 Mar 18.

Authors

Detian Li¹, Huiting Li², Danyan Chen³, Lihong Xue⁴, Huayong He⁵, Yanfang Feng⁶, Yang Ji⁷, Linzhang Yang⁸, Qingnan Chu⁹

Affiliations

¹ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
² School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
³ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; College of Horticulture, Jinling Institute of Technology, Nanjing 210038, China.
⁴ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; College of Resources and Environment Science, Nanjing Agricultural University, Nanjing 210095, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212001, China.
⁵ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212001, China.
⁶ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; College of Resources and Environment Science, Nanjing Agricultural University, Nanjing 210095, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212001, China. Electronic address: jaasfengyanfang@163.com.
⁷ College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
⁸ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
⁹ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain and Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.

PMID: 33773345
DOI: 10.1016/j.scitotenv.2021.146532

Abstract

With the favorable microporous structure and excellent adsorption capacity, clay-hydrochar composites (CHCs) serve as promising materials to mitigate greenhouse gas emissions (GHG) from the paddy fields. Three clays were co-pyrolyzed with hydrochar derived from poplar sawdust to obtain CHCs, which were applied to the paddy fields to investigate the effects on methane (CH₄) and nitrous oxide (N₂O) emissions. Three CHCs were labeled as bentonite-hydrochar composite (BTHC), montmorillonite-hydrochar composite (MTHC), and kaolinite-hydrochar composite (KTHC), respectively. The effects of these three CHCs on GHG emissions were determined by monitoring the dynamic CH₄ and N₂O emissions in the paddy soil column ecosystem during the rice-growing season. The results showed that compared with the control group, three CHCs significantly mitigated CH₄ and N₂O emissions by 21.4%-47.5% and 5.2%-36.8%, respectively. Furthermore, the fluorescent components result displayed CHCs increased humic-like content by 29.62%-59.72%. A structural equation model was used to assess the hypothesis mitigation mechanism, which exemplified that GHG emissions negatively correlated with pmoA and nosZ genes, possibly resulting in the CH₄ and N₂O mitigation. Among the three CHCs, the KTHC amendment mitigated the CH₄ and N₂O emissions by 47.5% and 36.8%, respectively, which was superior to BTHC and MTHC. Hence, it was recommended for application to the field. Overall, this study demonstrates the mitigating effects of CHCs on GHG emissions for the first time, and the reduced CH₄ and N₂O emissions could contribute to increased soil C and N retention for better agricultural nutrients management.

Keywords: Functional gene; Greenhouse gas; Hydrothermal carbonization; Kaolinite-hydrochar composite.