渭北黄土高原东部尧山林场主要人工林土壤肥力综合评价

Comprehensive Evaluation of Soil Fertility of Typical Stands in the East of Weibei Loess Plateau

为给陕西渭北黄土高原建设和管理提供依据,以尧山林场油松林、侧柏林、刺槐林等3种主要人工纯林为对象,利用常规测试方法和主成分分析法对林地土壤肥力进行了测定分析和综合评价。结果表明3种林分土壤有机质含量均随土层深度增加而逐渐下降,腐殖质层pH值显著高于其他土层;刺槐林碱解N含量随土层的增加而逐渐下降,腐殖质层有效P含量显著高于其他土层;油松林有机质含量显著高于侧柏和刺槐林;刺槐林土壤pH值和碱解N含量显著高于油松和侧柏林,速效K含量显著低于油松和侧柏林;土壤有效P含量油松林>侧柏>刺槐林;3种林分土壤综合肥力差异较大,肥力综合分值油松林(1.01)>侧柏林(-0.34)>刺槐林(-0.99);油松林有机质含量高、刺槐林碱解N含量高;油松和侧柏林地土壤碱解N亏缺,刺槐林地速效K缺乏。

Analysis and comprehensive evaluation of soil fertility in three typical stands——Pinus tabulaeformis,Platycladus orientalis and Robinia pseudoacacia in Yaoshan Forest Farm were conducted.The result showed that soil organic matter content in the three forest stands gradually decreased with the increase of soil layer depth,and the pH of humus layer was significantly higher than that of other soil layers.The alkaline hydrolysis N content of Robinia pseudoacacia stand decreased gradually with the increase of soil layer,and the effective phosphorus content of humus layer was significantly higher than that of other soil layers.From the standpoint of stand type,the organic matter content of Pinus tabulaeformis forest was significantly higher than that of Platycladus orientalis and Robinia pseudoacacia;the pH and alkaline hydrolysis N content of Robinia pseudoacacia forest were significantly higher than those of Pinus tabulaeformis and Platycladus orientalis,while the content of available potassium was significantly lower than those of Pinus tabulaeformis and Platycladus orientalis.The effective phosphorus content showed the order of Pinus tabulaeformis>Platycladus orientalis>Robinia pseudoacacia.The soil organic matter content of three typical stands decreases with the deepening of the soil layer.The soil chemical properties of different stand types were quite different,the Pinus tabulaeformis forest had higher organic matter content,and the Robinia pseudoacacia forest with higher alkaline hydrolysis N content.Alkaline hydrolysis N was deficient in Pinus tabulaeformis forest and Platycladus orientalis forest,and available potassium was deficient in Robinia pseudoacacia forest.