黄土丘陵区侵蚀环境不同坡面及坡位土壤理化特征研究

研究了黄土丘陵区纸坊沟流域阴阳坡面及不同坡位土壤水分、物理和养分特征,结果表明,与坡顶距离越远,表层土壤含水量由小变大。阴坡蒸发量小,土壤含水量较大。容重阴坡<阳坡,距坡顶越远,土壤容重、非活性孔度越小,孔隙比、活性孔度越大,同一坡向阳坡随土层加深土壤容重增大,阴坡表层土壤容重增加幅度较下层小,容重在剖面趋于均化。阴坡对土壤的改善优于阳坡,有利于植被生长。表层土壤全氮含量阴坡>阳坡,且随土层加深而减少。全氮和有机质在坡中下部累积。全磷在不同坡向和坡位变化不明显。速效钾在各坡位变化幅度较小且阴坡>阳坡。阴阳坡土壤各养分有向表层富集的趋势。坡面土壤容重与土壤孔隙比、活性孔度、毛管含水量和有机质呈极显著负相关,与土壤非活性孔度和表层土壤含水量呈显著正相关,土壤有机质和土壤全氮、速效钾呈极显著正相关。在对坡面进行植被恢复时,需结合坡面土壤变化规律,因地制宜,合理利用和开发土地资源,促进植被恢复演替。

Study on Soil Physical and Nutrients Properties of Different Slope Aspects and Positions in Eroded Loess Hilly Region

To find soil physical and chemical properties response to re-vegetation,the purpose of this study was to investigate soil water content,bulk density and related physical characters and soil nutrients of different position in sunny slope and shady slope in eroded hilly-gully loess region.The result showed that soil water content increased as the distance from the top of the slope increased and soil water content in the shady slope higher than that of the sunny slope because of the evaporation in the shady slope was less,but bulk density showed the opposity regulation.Furthermore,bulk density,non-capillary porocity decreased and porocity ratio,capillary porocity increased as the distance from the top of the slope increased on the same slope aspect,bulk density increased with the soil depth in the sunny slope,however,there was little change of bulk density in the shady slope.It was concluded that the soil properties in the shady slope was better than that of the sunny slope,it was more advantage to the vegetation grows.Meanwhile,soil total nitrogen in the shady slope was higher than that of the sunny slope and decreased with depth.Soil total nitrogen and soil organic matter accumulated in the middle and down slope.Available potassium changed less and its quantity in the shady slope was more than in the sunny slope.The soil nutrients were higher in the upper layer of the soil while soil bulk density very significant negative correlation with the porocity ratio,capillary porocity,capillary moisture capacity and soil organic matter,but significant positive correlation with non-capillary porocity and soil water content of the upper layer.There existed very significant positive correlation with soil organic matter and total nitrogen and available potassium.The results of this study recommened that considered more on physical and chemical properties of the slope soil when restoration on the slope,meanwhile reasonable used and exploited land resources to enhanced the vegetation rehabilitation.