高寒草地土壤理化性质特征及质量评价

Characteristics of soil physical and chemical properties and evaluation of soil quality of different types of alpine grasslands

以黄河源区4类高寒草地为研究对象,测定了0~20 cm土层土壤理化性质,并运用主成分分析法对土壤质量进行评价,结果表明:1)土壤容重和pH值表现均为高寒草原>人工草地>高寒草甸>沼泽草甸;土壤含水量、有机碳、全碳、氨氮、全氮含量均表现为沼泽草甸>高寒草甸>人工草地>高寒草原;土壤硝氮含量表现为人工草地>沼泽草甸>高寒草原>高寒草甸;土壤速效磷和全磷含量均表现为沼泽草甸>高寒草甸>人工草地>高寒草原;土壤速效钾和全钾含量均表现为人工草地>高寒草原>高寒草甸>沼泽草甸;2)土壤有机碳含量与全碳、氨氮、全氮、速效磷、全磷含量之间呈极显著正相关关系(P<0.01),土壤全碳含量与氨氮、全氮、速效磷、全磷含量之间呈极显著正相关关系(P<0.01),土壤碳氮磷元素呈强相关关系,三者之间高度耦合;3)在0~10、10~20以及0~20 cm土层,土壤质量高低排序均为沼泽草甸>高寒草甸>人工草地>高寒草原,各草地0~10 cm土层土壤质量均高于10~20和0~20 cm土层,0~20 cm土层土壤质量高于10~20 cm土层。

Different types of alpine grasslands in the source area of the Yellow River were research objects.The physical and chemical properties of 0~20 cm soil layer were measured andthe soil quality was also evaluated by principal component analysis.The results showed that: 1.The soil bulk density and pH from high to low both were alpine steppe>artificial grassland>alpine meadow > swamp meadow;the soil water content, organic carbon, total carbon, ammonia nitrogen and total nitrogen from high to low were all ranked as: swamp meadow>alpine meadow >artificial grassland>alpine steppe;the nitrate content from high to low was artificial grassland>swamp meadow > alpine steppe> alpine meadow;the contents of available phosphorus and total phosphorus from high to low were both as: swamp meadow > alpine meadow >artificial grassland >alpine steppe;the contents of available potassium and total potassium from high to low were both as: artificial grassland>alpine steppe> alpine meadow>swamp meadow.2.There was a significant positive correlation between soil organic carbon content and soil total carbon, ammonia nitrogen, total nitrogen, available phosphorus and total phosphorus content(P< 0.01).There was a significant positive correlation between soil total carbon content and soil ammonia nitrogen, total nitrogen, available phosphorus and total phosphorus content(P< 0.01).There was also a strong correlation between soil carbon, nitrogen and phosphorus, and the three were highly interconnected.3.In 0~10 cm, 10~20 cm and 0~20 cm soil layers, the order of soil quality from high to low was swamp meadow > alpine meadow >artificial grassland > alpine steppe.For each grassland the soil quality of 0~10 cm soil layer was higher than that of 10~20 cm and 0~20 cm soil layers, and the soil quality of 0~20 cm soil layer was higher than that of 10~20 cm soil layer.