开垦种草对高寒草甸土壤理化性质的影响

对玛曲高寒草甸天然草地及开垦种草8年和20年草地土壤理化性质进行了比较研究。结果表明，土壤含水量天然草地显著高于开垦种草8年草地；土壤容重0～10 cm土层天然草地显著高于开垦种草20年草地；0～60 cm土层土壤有机碳含量天然草地显著高于开垦种草草地，比开垦种草草地高38.66%。土壤全氮、速效氮、全磷和速效磷含量天然草地显著高于开垦种草草地。土壤全氮、速效氮和全磷含量随开垦种草年限增加逐渐下降。各样地土壤全氮、速效氮与土壤有机碳呈显著正相关关系。

Effects of cultivation on soil properties in alpine meadow

In this study we analyzed soil physical and chemical properties in the natural grassland and the cultivated oat (Avena sativa) grasslands of 8 (Ⅰ) and 20 (Ⅱ) years in alpine meadow of Maqu. There were significant differences in soil water content, soil organic carbon (SOC), total nitrogen, total phosphorus, available nitrogen and available phosphorus between the natural and the cultivated grassland. The soil bulk density of the natural grassland was significantly higher than that of Ⅱ in the 0 to 10 cm soil layer. The SOC of the natural grassland was 38.66% higher than cultivated grassland in the soil layer from 0 to 60 cm. Total nitrogen, available nitrogen, total phosphorus and available phosphorus of the natural grassland were also significantly higher than those of two cultivated grasslands (P<0.05). The total nitrogen, total phosphorus and available nitrogen of cultivated oat grasslands were decreased with the cultivated years increasing. The soil organic carbon had a significant linear relationship with total nitrogen and available nitrogen in the natural and cultivated grasslands.