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应用生态学报 ›› 2018, Vol. 29 ›› Issue (3): 857-864.doi: 10.13287/j.1001-9332.201803.023

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稻田土壤有机碳矿化及其激发效应对磷添加的响应

唐美玲1,2, 魏亮2, 祝贞科2, 李欢2, 周萍2, 葛体达2, 吴金水2, 王光军1*   

  1. 1中南林业科技大学生命科学与技术学院,长沙 410004;
    2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
  • 收稿日期:2017-05-18 出版日期:2018-03-18 发布日期:2018-03-18
  • 通讯作者: * E-mail: wanggj652@163.com
  • 作者简介:唐美玲,女,1993年生,硕士研究生. 主要从事稻田土壤碳循环的研究. E-mail: 3193067323@qq.com
  • 基金资助:

    本文由国家自然科学基金项目(41430860,41371304)、中国科学院战略性先导科技专项(XDB15020401)和湖南省自然科学基金项目(2016JJ3132)资助

Responses of organic carbon mineralization and priming effect to phosphorus addition in paddy soils.

TANG Mei-ling1,2, WEI Liang2, ZHU Zhen-ke2, LI Huan2, ZHOU Ping2, GE Ti-da2, WU Jin-shui2 , WANG Guang-jun1*   

  1. 1College of Life Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;
    2Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
  • Received:2017-05-18 Online:2018-03-18 Published:2018-03-18
  • Contact: * E-mail: wanggj652@163.com
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (41430860, 41371304), the Special Sub-Subject of Strategic Leading Science and Technology of Chinese Academy of Sciences (XDB15020401), and the Natural Science Foundation of Hunan Province (2016JJ3132)

摘要: 采用室内模拟培养和13C同位素标记技术相结合的研究方法,探讨了在葡萄糖与无机氮肥共施的条件下,土壤有机碳矿化及其激发效应对外源磷添加的响应,以揭示土壤有机碳矿化的碳磷耦合调控机制.结果表明: 外源磷的输入加快了CO2的释放,但抑制了CH4的释放;在整个土壤淹水培养期间,磷添加抑制了土壤碳矿化释放CH4总量的53.1%,其中外源葡萄糖-13C矿化成13CH4的总量降低了70.5%;磷添加促使通过微生物转化的葡萄糖-13C向易利用态碳库的分配比例增加了3.6%,显著提高土壤有机碳快库矿化速率,缩短土壤碳矿化周期.土壤培养前期,外源有机质的添加表现为短暂的负激发效应;随着葡萄糖不断矿化分解, CO2累积激发效应(PECO2)总体上呈现先增加后下降的趋势,而CH4累积激发效应(PECH4)稳步增加最终保持基本稳定状态;培养结束时(100 d),在磷添加条件下,PECO2增强32.3%,PECH4显著降低93.4%.冗余分析和Pearson分析表明,电导率、氧化还原电位和溶解有机碳对稻田土壤碳矿化的影响最为显著;速效磷与13CH4、PECH4呈极显著负相关.在外源有机质添加条件下,磷的添加能够抑制CH4排放及其激发效应,促进土壤有机质的矿化和养分释放,提高土壤原有有机碳的可利用性,促进稻田土壤有机碳循环.

关键词: 稻田土, 磷添加, 有机碳矿化, 激发效应

Abstract: To understand the coupled controlling of carbon (C) and phosphorus (P) on the minera-lization of soil organic carbon and amended substrates in paddy soil, we investigated the effects of P addition on the decomposition of organic carbon and its induced priming effect by using 13C isotope probing technique in microcosm. The results showed that P addition accelerated the release of CO2 but inhibited the release of CH4, leading to 53.1% reduction of total accumulated CH4 and 70.5% reduction of the 13CH4 derived from exotic glucose-13C. P addition altered the carbon distribution during the microbial turnover progress, with 3.6% of glucose-13C being transferred into the labile carbon pool, therein significantly increased potential of the mineralization rate of exogenous C. A transient negative priming effect was observed in the early stage of incubation. With time prolonging, the priming effect on CO2 emission (PECO2) generally increased and then decreased after a peak. The priming effect on CH4 emission (PECH4) kept increasing and finally fluctuated at a relative stable value until the end of the experiment (100 days). P addition increased PECO2 by 32.3% but reduced PECH4 by 93.4%. Results from the RDA and Pearson analysis showed that electric conductivity, oxidation-reduction potential and dissolved organic carbon significantly affected soil C mineralization. There were significantly negative correlations between available phosphorus (Olsen-P) and 13CH4, and between Olsen-P and PECH4. In conclusion, with the addition of exogenous organic matter, P application could reduce CH4 emissions and inhibit its priming effect, acce-lerate the mineralization of SOC, probably improve the nutrient supply, and thus enhance the avai-lability of organic C and promote C cycling in paddy soil.

Key words: paddy soil, priming effect, organic carbon mineralization, phosphorus addition