中文关键词稻田碳循环水分管理温室气体¹³C-CO₂连续标记法根际激发效应 英文关键词paddy soilcarbon cyclewater managementgreenhouse gas emission¹³C-CO₂ continuous labelingrhizosphere priming effect

作者	单位	E-mail
林森	中南林业科技大学环境科学与工程学院, 长沙 410004 中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125	982500950@qq.com
肖谋良	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
江家彬	贵州大学农学院, 贵阳 550025
魏亮	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
李科林	中南林业科技大学环境科学与工程学院, 长沙 410004	csfuklli@163.com
刘守龙	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
祝贞科	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125	zhuzhenke@isa.ac.cn
葛体达	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125
吴金水	中国科学院亚热带农业生态研究所, 亚热带农业生态过程重点实验室, 长沙 410125

中文摘要 作物根际沉积碳输入而引起的根际激发效应，对农田土壤碳排放通量和碳平衡起到关键的调控作用.在稻田生态系统中，由于频繁的干湿交替，土壤CO₂和CH₄排放以及根际激发效应明显有别于其他自然生态系统.因此，明确稻田生态系统干湿交替过程中水稻根际激发效应的方向与强度，对于减缓稻田温室气体排放具有重要意义.本研究采用¹³C-CO₂连续标记法，结合盆栽试验，研究干湿交替和持续淹水条件下，水稻生长以及根际激发效应的响应特征.结果表明，相对于持续淹水处理，干湿交替处理使水稻地上部和根系生物量以及根冠比显著提高，并增加了土壤微生物生物量.持续淹水条件下，¹³CO₂和¹³CH₄排放通量随水稻生长由10.2 μg·（kg·h）^-1和2.8 μg·（kg·h）^-1（63 d）增加到16.0 μg·（kg·h）^-1和3.2 μg·（kg·h）^-1（75 d）.而在干湿交替条件下，经过12 d的落干处理¹³CO₂和¹³CH₄排放通量分别降低了57.5%和88.1%.持续淹水条件下，CO₂和CH₄的根际激发效应表现为正激发效应，而且随水稻的生长而增加.而干湿交替处理下，经过12 d的落干处理，CO₂和CH₄的根际激发效应分别由0.29 mg·（kg·h）^-1和12.3 μg·（kg·h）^-1（63 d）降低到-0.39 mg·（kg·h）^-1和0.07 μg·（kg·h）^-1（75 d）.因此，干湿交替处理，能有效促进水稻生长和降低CH₄的累计排放量.合理地田间水分管理对于提高水稻产量和降低温室气体排放具有重要意义. 英文摘要 The rhizosphere priming effect (RPE) caused by carbon inputs from crop rhizodeposits plays a key role in regulating the carbon emission flux and carbon balance of farmland soils. Due to frequent alternations between dry and wet conditions, CO₂ and CH₄ emissions and the RPE in paddy field ecosystems are significantly different to those of other ecosystems. Therefore, it is of great significance to determine the direction and intensity of the rice RPE under alternations of dry and wet to limit greenhouse gas emissions. In this study, using a ¹³C-CO₂ continuous labeling method combined with a pot-based experiment, the response of rice growth and the RPE under alternating dry and wet and continuous flooding conditions was examined. The results showed that, compared with the continuous flooding treatment, the alternating dry and wet treatments significantly increased aboveground and root biomass and the root-to-root ratio, and also increased soil microbial biomass. Under continuous flooding conditions, fluxes of ¹³CO₂ and ¹³CH₄ increased with rice growth from 10.2 μg·(kg·h)^-1 and 2.8 μg·(kg·h)^-1 (63 d) to 16.0 μg·(kg·h)^-1 and 3.2 μg·(kg·h)^-1 (75 d), respectively. During the 12-day drying process, the emissions of ¹³CO₂ and ¹³CH₄ derived from rhizosphere deposited C decreased by 57.5% and 88.1%. Under continuous flooding conditions, the RPE for CO₂ and CH₄ were positive and increased with the growth of rice. Under the alternating dry and wet treatment, after 12 days of drying, the RPE for CO₂ and CH₄ was reduced from 0.29 mg·(kg·h)^-1 and 12.3 μg·(kg·h)^-1 (63 d) to -0.39 mg·(kg·h)^-1 and 0.07 μg·(kg·h)^-1 (75 d). Thus, alternating wet and dry treatment can effectively promote rice growth and reduce the cumulative emissions of CH₄. Therefore, adopting appropriate field water management is of great significance for increasing rice yields and mitigating greenhouse gas emissions.

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