川西北亚高山草地不同退化梯度草地土壤养分变化

通过对轻度退化、中度退化和重度退化3个不同退化程度的亚高山草地土壤的养分成分测定得出,随着草地退化程度的加剧,轻度到重度退化的草地土壤有机质含量分别比对照减少了38.94%,44.58%和48.49%,全氮含量逐渐减少(重牧除外),全磷、速效氮、速效磷和速效钾含量逐渐上升,但不同营养成分其变化幅度各有所不同,全钾含量基本无变化.试验结果同时显示,所有速效养分要比全价养分的变化幅度大,表层(0～10 cm)土壤养分受退化影响程度要比深层土壤大.

The changes of grassland soil nutrition at different degradation subalpine meadow of north-west in Sichuan

The series of nutritive ingredients of Subalpine meadow soil on the three grazing intensity of lightgrazing, middlegrazing and heavygrazing were studied in this study. The results showed that the contents of organic matter and total N degraded with the expansion of degradation degree. The contents of organic matter degraded 38.94%,44.58% and 48.49% than control respectively from light to heavy degradation degree. The contents of total P, available P, available K and available N increased while the content of total K was not significant deference than control. The change degree was certainly changed with the different nutritive ingredient. The change degree of all of the available nutrition was higher than one of total nutrition at the same time. Especially the influence of surface layer soil (0-10 cm) nutrition by the degradation was the larger than other one(lower 10 cm).