To explore the allelopathic mechanism of Euphorbia jolkinii Boiss， a degradation indicator species of mountain meadows in northwest Yunnan， in this study we analyzed its effects on soil phosphorus transformation and related indicators by adding different concentrations of 4-Nitrophenol （4-NP） and 2-Phenethylamine （2-PEA） to the soil. The results showed that both allelochemicals significantly increased soil microbial biomass phosphorus， aluminum-bound phosphorus， calcium-bound phosphorus， and moderately reactive organic phosphorus content， decreased pH and iron-bound phosphorus， occluded phosphorus， moderately stable and highly stable organic phosphorus content （P<0.05）， and promoted the proliferation of bacteria and actinomycetes. 4-NP significantly enhanced phytase activity and reduced acid phosphatase activity. 2-PEA significantly increased acid phosphatase， phytase， and phosphodiesterase activities， while reduced alkaline phosphatase activity （P<0.05）. In summary， the addition of 4-NP and 2-PEA directly affects soil physicochemical properties， changes the content of organic and inorganic phosphorus components， indirectly achieves the accumulation of soil nutrients in its rhizosphere environment， and promotes its further expansion.

Euphorbia jolkinii Boiss  /  Allelochemicals  /  Mountain meadows  /  Soil phosphorus transformation