Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (7): 811-822.DOI: 10.17521/cjpe.2021.0280

• Research Articles • Previous Articles     Next Articles

Interaction of soil arbuscular mycorrhizal fungi and plant roots acts on maintaining soil phosphorus availability under nitrogen addition

XIE Huan1, ZHANG Qiu-Fang2, CHEN Ting-Ting1, ZENG Quan-Xin1, ZHOU Jia-Cong1, WU Yue1, LIN Hui-Ying1, LIU Yuan-Yuan1, YIN Yun-Feng1, CHEN Yue-Min1,*()   

  1. 1State Key Laboratory of Subtropical Mountain Ecology, School of Geographical Science, Fujian Normal University, Fuzhou 350007, China
    2College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
  • Received:2021-08-02 Accepted:2021-12-09 Online:2022-07-20 Published:2022-01-07
  • Contact: CHEN Yue-Min
  • Supported by:
    Natural Science Foundation of Fujian Province(2020J01142)

Abstract:

Aims Phosphorus is one of the major limiting nutrients for plant growth in subtropical areas, whereas increasing nitrogen deposition may be a limiting factor in determining the availability of soil phosphorus. Here, focusing on soil microorganisms and plant fine roots, we explored the transformation of soil phosphorus to unravel the maintenance of soil phosphorus supply and plant productivity with low availability under nitrogen deposition.

Methods At the Fuzhou Changʼan Mountain in Fujian Province, China, control (0 kg·hm-2·a-1), low nitrogen (40 kg·hm-2·a-1), and high nitrogen (80 kg·hm-2·a-1) treatments were set up to simulate nitrogen addition. Soil and root samples of Cunninghamia lanceolata seedlings were then collected to comprehensively analyze soil phosphorus and nutrient contents as well as microbiological-plant root characteristics.

Important findings The results showed that the contents of soil labile organic phosphorus, moderately labile inorganic phosphorus and occluded phosphorus were significantly increased, whereas those of primary mineral phosphorus and moderately labile organic phosphorus decreased under the low nitrogen treatment as compared to the control treatment. However, there were no significant changes under the high nitrogen treatment. Redundancy analysis indicated that soil acid phosphatase activity, relative abundance of mycorrhizal fungi, soil microbial biomass phosphorus content, and root biomass were important soil microbiological-plant root characteristics factors that could explain the changes in soil phosphorus components. Variance partitioning analysis revealed that the soil microbiological-plant root characteristics synergy explained 57% of the alternations in soil phosphorus components, whereas correlation analysis showed a significant positive correlation between the relative abundance of mycorrhizal fungi and root biomass. Overall, these results suggest that mycorrhizal colonization is promoted under a low level of nitrogen input and the synergistic action of mycorrhizal fungi and C. lanceolata fine roots promotes the conversion of moderately labile organic and primary mineral phosphorus to labile phosphorus, thus maintaining the growth of C. lanceolata seedlings.

Key words: nitrogen addition, phosphorus, microbiologic characteristic, root characteristic, Cunninghamia lanceolata, seedling