Soil Macropore Structure Characterized by X-Ray Computed Tomography Under Different Land Uses in the Qinghai Lake Watershed, Qinghai-Tibet Plateau  

作　　者：HU Xia LI Zongchao LI Xiaoyan WANG Pei ZHAO Yunduo LIU Lianyou LU Yanli 

机构地区：[1]State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University,Beijing 100875( China) [2]School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875( China) [3]Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875( China)

出　　处：《Pedosphere》2018年第3期478-487,共10页土壤圈（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 41471018 and 41730854)

摘　　要：Quantification of soil macropores is important to enhance our understanding of preferential pathways for water, air, and chemical movement in soils. However, the soil architecture of different land uses is not well understood in elusive alpine regions. The objective of this study was to quantify the architecture of soil macropores in a Kobresia meadow, farmland, and sand in the Qinghai Lake watershed of northeastern Qinghai-Tibet Plateau, China using X-ray computed tomography. Nine soil cores at 0-50 cm depth were collected at three sites with three replicates. At each site, the three collected cores were scanned using a GE HiSpeed FX/i medical scanner （General Electric, USA）. To analyze soil architecture, the number of macropores, maeroporosity, and mean macropore equivalent diameter within the 50 cm soil profile were determined from the X-ray computed tomography. Analysis of variance indicated that land use significantly influenced macroporosity, mean macropore equivalent diameter, and number of macropores. The soils of the Kobresia meadow and farmland had greater macroporosity and developed deeper and longer maeropores than that of sand. For the Kobresia meadow, macropores were distributed mainly in the 0-10 cm soil layer, while they were distributed in the 0-20 cm soil layer for the farmland. The large number of macropores observed in the soils of the Kobresia meadow and farmland could be attributed to greater root development. The results of this study provided improved quantitative evaluation of a suite of soil macropore features with significant implications for non-equilibrium flow prediction and chemical transport modeling in soils.Quantification of soil macropores is important to enhance our understanding of preferential pathways for water, air, and chemical movement in soils. However, the soil architecture of different land uses is not well understood in elusive alpine regions. The objective of this study was to quantify the architecture of soil macropores in a Kobresia meadow, farmland, and sand in the Qinghai Lake watershed of northeastern Qinghai-Tibet Plateau, China using X-ray computed tomography. Nine soil cores at 0–50 cm depth were collected at three sites with three replicates. At each site, the three collected cores were scanned using a GE Hi Speed FX/i medical scanner(General Electric, USA). To analyze soil architecture, the number of macropores, macroporosity, and mean macropore equivalent diameter within the 50 cm soil profile were determined from the X-ray computed tomography. Analysis of variance indicated that land use significantly influenced macroporosity, mean macropore equivalent diameter, and number of macropores. The soils of the Kobresia meadow and farmland had greater macroporosity and developed deeper and longer macropores than that of sand. For the Kobresia meadow, macropores were distributed mainly in the 0–10 cm soil layer, while they were distributed in the 0–20 cm soil layer for the farmland. The large number of macropores observed in the soils of the Kobresia meadow and farmland could be attributed to greater root development. The results of this study provided improved quantitative evaluation of a suite of soil macropore features with significant implications for non-equilibrium flow prediction and chemical transport modeling in soils.

关 键 词：FARMLAND Kobresia meadow MACROPOROSITY root development SAND soil architecture 

分 类 号：S152[农业科学—土壤学]