【摘要】 依托中国科学院额尔古纳森林草原过渡带生态系统研究站硫添加(0、1、2、5、10、15、20、50 g·m^-2·a^-1)试验平台，分析了表土磷组分的变化动态，测定了土壤无机磷组分(Ca₂-P、Ca₈-P、Al-P、Fe-P、Ca₁₀-P、O-P)和有机磷组分（按照其活性由大到小依次为活性有机磷、中等活性有机磷、中稳性有机磷、高稳性有机磷）,研究了外源硫添加对草原土壤磷组分的影响。结果表明：随硫添加量的增加，土壤Al-P和Ca₈-P质量分数显著增加，土壤Ca₂-P和Ca₁₀-P质量分数显著降低，硫添加降低土壤pH值，促进了易溶性无机磷（Ca₂-P）的溶解以及难溶性无机磷(Ca₁₀-P)向中等活性无机磷（Al-P、Ca₈-P）的转化。随硫添加量的增加，土壤的活性、中等活性及高稳性有机磷质量分数降低，而中稳性有机磷质量分数增加，表明高量硫添加有利于中稳性有机磷的积累。硫添加增加了土壤有效磷质量分数，表明由硫添加诱导的土壤酸化可提高土壤磷的有效性。更多还原

【Abstract】 Based on a field experiment with S addition(0、1、2、5、10、15、20、50 g·m^-2·a^-1) in Inner Mongolia Grassland Ecosystem Research Station of Chinese Academy of Sciences.The changes of P fractions in the topsoil were examined and the effects of exogenous S addition on grassland soil P fractions were studied. Soil inorganic P fractions include Ca₂-P、Ca₈-P、Al-P、Fe-P、Ca₁₀-P、O-P and soil organic P fractions include labile organic P, moderate-labile organic P, moderate-stable organic P, and high-stable organic P. Results showed that S addition significantly increased the mass fraction of soil Al-P and Ca₈-P, but decreased the mass fraction of soil Ca₂-P and Ca₁₀-P. S addition promoted the dissolution of soluble inorganic P（Ca₂-P） and the transformation of insoluble inorganic P(Ca₁₀-P) to moderate activity inorganic P（Al-P, Ca₈-P） by reducing soil pH. S addition decreased the mass fraction of soil labile, moderate-labile and high-stable organic P, but increased the mass fraction of soil moderate-stable organic P. This suggested that S addition accelerated the accumulation of moderate-stable organic P. S addition significantly increased the mass fraction of soil Olsen-P, suggested that S addition induced soil acidification improved soil P availability.更多还原