Aims In this study, we examine the rhizosphere processes influencing organic P (P o ) utilization in soil with low inorganic P (P i ) availability and how they change with plant development. Interactions between plants and the rhizosphere microbial community triggered by P deficiency may provide insights into the role of P availability on degradation of soil organic matter (SOM). Methods Maize ( Zea mays ) plants were grown in low P containing soil. Soil pH, potential acid phosphatase activities, soil C and P pools, microbial biomass C and P, microbial community structure, and plant P content were analyzed at different vegetative growth stages (VGS). Results At early VGS, the plants were P deficient which correlated with greater rhizosphere potential acid phosphatase activity, degradation of SOM and a reduction in the P o pool. At late VGS, the plants appeared to recover which correlated with a decrease in Meh (III) extractable P, an increase in microbial biomass C and P, change in microbial community structure, and greater total P (TP) in the plant biomass. Conclusions The mineralization of organic C and P o are coupled in low P soil where N is not limited. The overall findings from this study advance our understanding of the coupled biogeochemical rhizosphere processes controlling P cycling at different plant growth stages and notably the importance of P o to the overall P needs of plants in soil with low P i availability.

中文翻译：

---

土壤磷含量低触发玉米生长阶段特定的根际过程，导致有机磷矿化

目的 在本研究中，我们研究了影响无机磷 (P i ) 有效性低的土壤中有机磷 (P o ) 利用率的根际过程，以及它们如何随植物发育而变化。由缺磷引发的植物与根际微生物群落之间的相互作用可能有助于深入了解磷的有效性对土壤有机质 (SOM) 降解的作用。方法玉米（Zea mays）植株在低磷土壤中生长。分析了不同营养生长阶段（VGS）的土壤 pH、潜在酸性磷酸酶活性、土壤 C 和 P 库、微生物生物量 C 和 P、微生物群落结构和植物 P 含量。结果在早期的 VGS 中，植物缺磷，这与更大的根际潜在酸性磷酸酶活性、SOM 降解和 P o 库减少相关。在 VGS 后期，植物似乎恢复了，这与 Meh (III) 可提取 P 的减少、微生物生物量 C 和 P 的增加、微生物群落结构的变化以及植物生物量中的总 P (TP) 增加相关。结论 有机碳和磷的矿化在氮不受限制的低磷土壤中是耦合的。这项研究的总体发现促进了我们对控制不同植物生长阶段磷循环的耦合生物地球化学根际过程的理解，特别是 P o 对低 P i 可用性土壤中植物整体磷需求的重要性。结论 有机碳和磷的矿化在氮不受限制的低磷土壤中是耦合的。这项研究的总体发现促进了我们对控制不同植物生长阶段磷循环的耦合生物地球化学根际过程的理解，特别是 P o 对低 P i 可用性土壤中植物整体磷需求的重要性。结论 有机碳和磷的矿化在氮不受限制的低磷土壤中是耦合的。这项研究的总体发现促进了我们对控制不同植物生长阶段磷循环的耦合生物地球化学根际过程的理解，特别是 P o 对低 P i 可用性土壤中植物整体磷需求的重要性。