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 (P0.05). 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.