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以山西省阳高县大型径流观测场为依托,选择土壤机械组成、孔隙度、毛管孔隙度、有机质、全氮、碱解氮、速效磷和速效钾8项反映土壤特性的因子作为评价指标,采用主成分分析对裸坡、荒坡、柠条(Caragana korshinskii)、沙棘(Hippophae rhamnoides)、油松(Pinus tabuliformis)和苜蓿(Medicago sativa)6种不同植被条件下土壤质量进行综合评价。结果表明:8项理化性质指标可归纳为有机质因子、质地因子和孔隙因子3个公因子;柠条、沙棘、油松和苜蓿4种人工植被土壤有机质因子和孔隙因子均高于荒地;除苜蓿外,其他3种人工植被土壤质地因子均高于荒地;而裸地土壤的3个公因子均处于最低水平;苜蓿、柠条、沙棘、油松、荒地、裸地土壤质量综合指数分别为0.596、0.584、0.495、0.481、0.305和0.194。说明苜蓿、柠条、沙棘和油松4种人工植被均能促进土壤质量改善,其中苜蓿和柠条的优势更明显,裸坡则使土壤退化。
Based on the large-scale runoff observation field in Yanggao County, Shanxi Province, eight factors reflecting soil characteristics such as soil mechanical composition, porosity, capillary porosity, organic matter, total nitrogen, available nitrogen, available phosphorus and available potassium were selected as evaluation indexes. Principal component analysis (PCA) was used to evaluate the soil quality under six different vegetation conditions: bare slope, Caragana korshinskii, Hippophae rhamnoides, Pinus tabuliformis and Medicago sativa. The results showed that the eight physical and chemical indexes could be grouped into three common factors of organic matter, texture factor and pore factor. Soil organic matter and pore factor of four kinds of artificial vegetation such as Caragana korshinskii, Hippophae rhamnoides, Pinus tabulaeformis and Medicago sativa were higher than those of wildland. The soil texture factors of three kinds of artificial vegetation were higher than those of wildland, while the three common factors of bare soil were the lowest. The comprehensive indexes of soil quality of alfalfa, Caragana korshinkii, Seabuckthorn, Pinus tabulaeformis, wasteland and bare land were 0.596 , 0.584, 0.495, 0.481, 0.305 and 0.194. All four artificial alfalfa, Caragana, Seabuckthorn and Pinus tabulaeformis plants could promote the soil quality improvement. The advantages of alfalfa and Caragana korshinskii were more obvious, while the bare slope caused the soil degradation.