Three-year elevated carbon dioxide concentration does not enhance soil organic carbon quantity due to simultaneously facilitated carbon input and decomposition in a single rice paddy soil evidenced by natural 13 C tracing.

Autor: Tang S; School of Breeding and Multiplication, Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China; Faculty of Agriculture, Yamagata University, Tsuruoka 997-8555, Japan., Wu Y; School of Breeding and Multiplication, Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China., Meng L; School of Breeding and Multiplication, Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China., Sakai H; Institute for Agro-Environmental Sciences, NARO, 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan., Hasegawa T; Institute for Agro-Environmental Sciences, NARO, 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan., Xu X; State Key Laboratory of Atmospheric Environment and Extreme Meteorology, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China., Guo Z; Soil and Fertilizer Research Institute, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, China., Cheng W; Faculty of Agriculture, Yamagata University, Tsuruoka 997-8555, Japan. Electronic address: cheng@tds1.tr.yamagata-u.ac.jp.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Dec 20; Vol. 957, pp. 177605. Date of Electronic Publication: 2024 Nov 23.
DOI: 10.1016/j.scitotenv.2024.177605
Abstrakt: Soil organic carbon (SOC) markedly contributes to maintaining soil nutrient cycling and mitigating climate change. Elevated carbon (C) dioxide concentration ([CO 2 ]) is widely expected to improve crop yield and increase C storage; however, its effects on rice growth and SOC dynamics remain greatly unclear. Therefore, a three-year (2007-2009) chamber experiment with two [CO 2 ] treatments (380 vs. 680 ppm) was conducted during rice growing seasons. Ultisol soil, taken from a sugarcane (C 4 plant) field on Ishigaki island, Okinawa, was used to grow rice (C 3 plant). The natural 13 C tracing method was utilized to measure the fraction of SOC derived from rice plant, and δ 13 C values and concentrations of CO 2 and CH 4 dissolved in soil solutions were determined. Elevated [CO 2 ] significantly increased rice aboveground biomass (AGB) by 11.8 %-28.8 % and assimilated C content by 12.2 %-28.3 %. However, no significant differences were observed in SOC, total nitrogen (N) content, and the C/N ratios between ambient and elevated [CO 2 ]. Elevated [CO 2 ] induced markedly lower δ 13 C values in both plant and soil samples relative to ambient [CO 2 ]. The annual fractions of plant-derived C input ranged from 5.0 % to 21.2 % in ambient [CO 2 ] and from 5.6 % to 21.9 % in elevated [CO 2 ] without significant differences. Elevated [CO 2 ] stimulated marked increases in dissolved CO 2 and CH 4 concentrations, and δ 13 C values of CH 4 , indicating a positive priming effect of elevated [CO 2 ] on native SOC decomposition for methanogenesis. In conclusion, elevated [CO 2 ] did not affect SOC accumulation by simultaneously increasing C input evidenced by increased AGB, and SOC decomposition as CO 2 and CH 4 emissions, hence resulting in a stable SOC quantity in rice paddy ecosystems. Our study delves in the nexus between C input and soil C decomposition under elevated CO 2 condition, highlighting its significance in prediction of the responses of C storage in paddy ecosystems to future climate change.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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