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研究高寒草甸添加不同磷(P)肥梯度对土壤养分状况与土壤微生物的影响,探明土壤养分变化和微生物功能多样性的差异及其互作关系。采用常规实验室分析和Biolog-ECO生态板法,研究了0 g m~(-2)(CK),10 g m~(-2)(P10),20 g m~(-2)(P20),30 g m~(-2)(P30)4个施P肥水平下土壤养分及土壤微生物功能多样性的变化规律。结果表明:P肥显著增加高寒草甸的速效养分、全磷和全钾的含量,但对有机质、全氮和pH无显著影响。AWCD值在表层(0~10 cm)无显著变化,但深层(10~20 cm)则为P20>P30>P10>CK。土壤微生物多样性在表层随施肥量增加而降低,而深层随施肥量增加而升高。主成分分析表明,氨基酸类、胺类、酯类是土壤微生物利用的主要碳源类型,其中在表层糖类和酯类随施肥量增加而降低,而深层碳源利用均在P20处理下显著提高。冗余分析表明,土壤速效氮、速效磷和速效钾含量是影响高寒草甸土壤微生物功能多样性和代谢活性的主要因子。因此,在退化高寒草甸适量添加P肥有利于生态系统的恢复重建。
The effects of different phosphorus (P) fertilizers gradients on the soil nutrient status and soil microbes in alpine meadow were studied, and the differences in soil nutrients and microbial functional diversity and their interactions were also explored. The effects of 0 gm ~ (-2) CK, 10 gm ~ (-2) (P10), 20 gm ~ (-2) (P20), 30 gm ~ (-2) (P30) soil fertility and the functional diversity of soil microorganisms under four P fertilization levels. The results showed that P fertilizer significantly increased the contents of available nutrients, total phosphorus and total potassium in alpine meadow, but had no significant effect on organic matter, total nitrogen and pH. AWCD values did not change significantly in the surface layer (0-10 cm), but P20> P30> P10> CK in deep layers (10-20 cm). Soil microbial diversity decreased with the increase of fertilizer application in the surface layer, but increased with the increase of fertilizer application in the deeper layer. Principal component analysis showed that amino acids, amines and esters were the main types of carbon sources for soil microbial utilization. The contents of carbohydrates and esters decreased with the increase of fertilizer application, while the utilization of deep carbon sources increased significantly under P20 treatment . Redundancy analysis showed that soil available N, available P and available K were the main factors affecting the microbial functional diversity and metabolic activity of alpine meadow soil. Therefore, the appropriate amount of P fertilizer in the degraded alpine meadow is conducive to ecosystem restoration and reconstruction.