Water-washed hydrochar in rice paddy soil reduces N2O and CH4 emissions: A whole growth period investigation

Danyan Chen; Yibo Zhou; Cong Xu; Xinyu Lu; Yang Liu; Shan Yu; Yanfang Feng

doi:10.1016/j.envpol.2021.116573

Water-washed hydrochar in rice paddy soil reduces N₂O and CH₄ emissions: A whole growth period investigation

Environ Pollut. 2021 Apr 1:274:116573. doi: 10.1016/j.envpol.2021.116573. Epub 2021 Jan 22.

Authors

Danyan Chen¹, Yibo Zhou², Cong Xu³, Xinyu Lu⁴, Yang Liu⁵, Shan Yu⁶, Yanfang Feng³

Affiliations

¹ College of Horticulture, Jinling Institute of Technology, Nanjing, 210038, China.
² Nanjing Extension Center for Agricultural Equipment, Nanjing, 210036, China.
³ Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Nanjing, 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212001, China.
⁴ Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Nanjing, 210014, China; College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China.
⁵ Institute of Agricultural Information, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China. Electronic address: liuyang@jaas.ac.cn.
⁶ Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Nanjing, 210014, China; School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China.

PMID: 33529901
DOI: 10.1016/j.envpol.2021.116573

Abstract

Hydrochar (HC), an environment-friendly material, enhances soil carbon sequestration and mitigate greenhouse gases (GHGs) emissions in croplands. In this study, the water-washed HC (WW-HC) was applied to paddy soil to investigate effects on nitrous oxide (N₂O) and methane (CH₄) emissions during rice growth period. Four treatments, namely control (without N fertilizer and WW-HC), N fertilizer (WW-HC00), N fertilizer with 0.5 wt% WW-HC (WW-HC05) and N fertilizer with 1.5 wt% WW-HC (WW-HC15), were established. Results showed the WW-HC addition reduced N₂O and CH₄ emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) during the growing season. Moreover, the WW-HC application reduced N₂O cumulative emission (P < 0.05) (by 28.6% and 23.8% for WW-HC05 and WW-HC15, respectively). It was mainly due to the reduced ratio of (nirK + nirS) to nosZ under WW-HC15 (P < 0.05). Compared with WW-HC00, the WW-HC05 reduced CH₄ cumulative emissions by 14.8%, while the WW-HC15 increased by 9.7%. This might be ascribed to the significantly reduced expression of the methanogenic mcrA gene and ratio of mcrA to pmoA by WW-HC (P < 0.05). The WW-HC05 amendment decreased GWP and GHGI by 18.6% and 32.5%, respectively. Furthermore, the WW-HC application greatly improved nitrogen use efficiency by 116-145% compared with the control. Our study indicates the WW-HC application is a promising GHGs mitigation practice in paddy fields.

Keywords: Global warming potential (GWP); Greenhouse gases (GHGs); Paddy soil; Soil functional genes; Water-washed hydrochar.

MeSH terms

Agriculture
Methane
Nitrous Oxide / analysis
Oryza*
Soil*
Water

Substances

Soil
Water
Nitrous Oxide
Methane