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Chinese Journal of Applied Ecology ›› 2018, Vol. 29 ›› Issue (3): 857-864.doi: 10.13287/j.1001-9332.201803.023

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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)

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