The effect of integrated rice-frog ecosystem on rice morphological traits and methane emission from paddy fields

Kaikai Fang; Wei Dai; Huiyan Chen; Jun Wang; Hui Gao; Zhimin Sha; Linkui Cao

doi:10.1016/j.scitotenv.2021.147123

The effect of integrated rice-frog ecosystem on rice morphological traits and methane emission from paddy fields

Sci Total Environ. 2021 Aug 20:783:147123. doi: 10.1016/j.scitotenv.2021.147123. Epub 2021 Apr 16.

Authors

Kaikai Fang¹, Wei Dai¹, Huiyan Chen¹, Jun Wang¹, Hui Gao¹, Zhimin Sha², Linkui Cao³

Affiliations

¹ School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
² School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Key Laboratory of Technology and Model for Cyclic Utilization from Agricultural Resources, Ministry of Agriculture and Rural, China. Electronic address: zhiminsha@sjtu.edu.cn.
³ School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China. Electronic address: clk@sjtu.edu.cn.

PMID: 34088155
DOI: 10.1016/j.scitotenv.2021.147123

Abstract

Integrated Rice-frog Ecosystem (IRFE) has the potential to reduce methane (CH₄) emission and maintain yields from paddy fields. However, the quantitative relationship between rice morphological traits and CH₄ emission remains to be explored. In this study, a 2-year field experiment was conducted to evaluate the effect of IRFE on rice morphological traits and CH₄ emission from paddy fields and the ecological mechanisms. This study was conducted to analyze twelve aboveground and eight underground rice morphological traits, rice yields, and CH₄ flux and emission from the paddy fields with six frog densities (0, 3750, 7500, 15,000, 30,000, and 60,000 frogs ha^-1). The results showed that IRFE reduced CH₄ emission by 24.70%-41.75% and 21.68%-51.21% in the 2018 and 2019 rice growth seasons, respectively. Moreover, CH₄ emission decreased with the increase of frogs. Frogs also increased the diameter, biomass, and volume of rice roots, thus promoting rice growth. Root biomass, thousand-grain weight, and harvest index were also closely related to the yield. Root porosity and oxygen secretion capacity were negatively correlated with CH₄ flux. Frogs increased root porosity and oxygen secretion, thereby reducing CH₄ emission. The present study demonstrated that reducing CH₄ emission and improving rice yields could be simultaneously achieved by altering rice morphological traits in IRFE.

Keywords: Frogs; Methane emission; Rice yields; Root oxygen secretion capacity; Root porosity.