Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha 410125, PR China; Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Hunan Agricultural University, Changsha 410128, PR China.
Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha 410125, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Sci Total Environ. 2018 Jul 1;628-629:53-63. doi: 10.1016/j.scitotenv.2018.01.314. Epub 2018 Feb 13.
Phosphorus (P) acquisition by plants from soil organic P mainly relies on microorganisms. Examining the community of functional microbes that encode phosphatases (e.g. PhoD) under different fertilization managements may provide valuable information for promoting soil organic P availability. Here, we investigated how the abundance and community diversity of phoD-harboring bacteria responded to long-term fertilization in Karst soils. Six fertilization treatments were designed as follows: non-fertilized control (CK), inorganic fertilization only (NPK), and inorganic fertilization combined with low- and high amounts of straw (LSNPK and HSNPK), or cattle manure (LMNPK and HMNPK). We found that soil available phosphorus (AP) content and the activity of alkaline phosphatase (ALP) were significantly higher in all combined inorganic/organic fertilization treatments, while the abundance of the phoD gene was only higher in the HMPNK treatment, compared to NPK. The combination of inorganic/organic fertilizations had no effect on the diversity of phoD genes compared to NPK alone, but the phoD gene richness was greater in these treatments as compared to the control. Only organic fertilization combinations with high amounts of organic matter (both HSNPK and HMNPK) significantly affected the phoD community structure. A structure equation model demonstrated that soil organic carbon (SOC), rather than P, greatly affected the phoD community structure, suggesting that organic P mineralization in soils is decoupled from C mineralization. Our results suggested that optimized combinations of inorganic/organic fertilizations could promote P availability via regulating soil phoD-harboring bacteria community diversity and ALP activity.
植物从土壤有机磷中获取磷主要依赖于微生物。研究不同施肥管理下编码磷酸酶（如 PhoD）的功能微生物群落，可能为促进土壤有机磷的有效性提供有价值的信息。在这里，我们研究了长期施肥对喀斯特土壤中 phoD 携带细菌的丰度和群落多样性的影响。设计了 6 种施肥处理，分别为：不施肥对照（CK）、仅施无机肥（NPK）以及无机肥与低量和高量秸秆（LSNPK 和 HSNPK）或牛粪（LMNPK 和 HMNPK）相结合的处理。我们发现，与 NPK 相比，所有无机/有机结合施肥处理均显著提高了土壤有效磷（AP）含量和碱性磷酸酶（ALP）活性，但 phoD 基因的丰度仅在 HMPNK 处理中较高。与单独 NPK 相比，无机/有机结合施肥对 phoD 基因多样性没有影响，但与对照相比，这些处理中的 phoD 基因丰富度更高。只有高量有机物（HSNPK 和 HMNPK）的有机与无机结合施肥组合显著影响了 phoD 群落结构。结构方程模型表明，土壤有机碳（SOC）而不是 P 极大地影响了 phoD 群落结构，这表明土壤中有机磷的矿化与 C 的矿化是解耦的。我们的结果表明，优化的无机/有机施肥组合可以通过调节土壤 phoD 携带细菌群落多样性和 ALP 活性来促进磷的有效性。
