高寒草地土壤理化性质特征及质量评价

Characteristics of soil physical and chemical propertiesand evaluation of soil quality of different typesof alpine grasslands

摘要:

以黄河源区4类高寒草地为研究对象，测定了0~20cm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(犘＜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(犘＜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0~20cm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0~10cm土层土壤质量均高于10~20 和0~20cm土层，0~20cm土层土壤质量高于10~20cm土层。

Abstract:

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.