三江源区高寒草原草地不同退化程度土壤养分变化

分别对轻度退化、重度退化和极度退化的高寒草原草地土壤养分进行测定。结果表明：随着高寒草原退化程度加剧，土壤有机质含量逐渐减少，由对照的90．75g／kg降低到极度退化的18．74g／kg。全氮、碱解氮含量逐渐减少，而全磷、全钾、速效钾和碳酸钙含量逐渐增加，但不同养分成分变化幅度各有所不同，速效磷含量及pH基本保持不变，土壤速效养分受退化程度影响较大，其变化幅度明显高于全量养分，表层土壤养分受退化影响的程度较深层土壤大。

The changes of alpine grassland soil nutrition at different deteriorate degree on high mountain meadow of Three River Source

The series of nutritive ingredients of high mountain meadow soil, heavy degree degeneration and deteriorate extremely were studied in this study. The zesults showed that the contents of organic matter decreased gradually with the expansion of deteriorate degree, from fight degree the 90.75 g/kg of the degeneration be as low as to deteriorate extremely of 18.74 g/kg, and the contents of total N, the alkaline N reduced graduaUy, but the contents of total P, total K, available K and CaCO3 increased gradually. The change degree was certainly changed with the different nutritive ingredients, the available P and pH were not significant deference. The change degree of all of the available nutrition was higher than one of total nutrition.