Spatial variability and scale effect of soil bulk density of farm land in South China
XU Cuilan1, HOU Shunan1, YAO Zidong2, ZHANG Fei3, SHE Dongli3
1. Jiangsu Provincial Center for Land Consolidation and Rehabilitation, Nanjing, Jiangsu 210017, China; 2. College of Environment, Hohai University, Nanjing, Jiangsu 210098, China; 3. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China
Abstract：Taking a typical farm land in South China as the test field, the spatial variability and scale effect of bulk density of soils harvested at different soil depths(0-10, 10-20 cm)in the selected field were analysed by using classical statistical and geostatistical methods, and the spatial interpolation of soil bulk density in the field was estimated. The results indicated that the coefficient of variation(CV)of bulk density was small and the variation was weak. A semi-variogram analysis showed that the C0/(C0+C)values of the measured soil bulk density were lower than 10%, indicating the spatial heterogeneity resulted from the spatial variability of soil bulk density was significant. For the scale effect, the CV decreased firstly and then increased with increasing sampling interval. By adjusting the location of sampling points("re-sampling"), it was found that the CV of soil bulk density was small(6.32%-7.92%)and the correlation distance decreased when the sampling interval increased. It was suggested that the sampling interval affected CV a little after the interval was decreased to a certain value. The spatial distribution pattern of soil bulk density in two layers also showed a spatial correlation based on the density spatial interpolation and contours, i.e. a significant positive correlation with a correlation coefficient of 0.76. Furthermore, the spatial variability of soil bulk density was affected by human activities largely.
徐翠兰, 侯淑楠, 姚紫东, 张飞, 佘冬立. 南方农田土壤容重空间变异性及其尺度效应[J]. 排灌机械工程学报, 2017, 35(5): 424-429.
XU Cuilan, HOU Shunan, YAO Zidong, ZHANG Fei, SHE Dongli. Spatial variability and scale effect of soil bulk density of farm land in South China. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(5): 424-429.
[1]WANG S L, MA C. The spatial heterogeneity of the soil bulk density under different management types of Pinus koraiensis forests[J]. Advanced materials research, 2013,726/727/728/729/730/731:4315-4318.[2]胡伟, 邵明安,王全九. 黄土高原退耕坡地土壤水分空间变异的尺度性研究[J]. 农业工程学报,2005,21(8):11-16. HU Wei, SHAO Ming′an, WANG Quanjiu. Scale-dependency of spatial variability of soil moisture on a degraded slope-land on the Loess Plateau[J]. Transactions of the CSAE, 2005,21(8):11-16.(in Chinese)[3]徐英,陈亚新,史海滨,等. 土壤水盐空间变异尺度效应的研究[J]. 农业工程学报,2004,20(2):1-5. XU Ying, CHEN Yaxin, SHI Haibin, et al. Scale effect of spatial variability of soil water-salt[J]. Transactions of the CSAE, 2004,20(2):1-5.(in Chinese)[4]张继光, 陈洪松,苏以荣,等. 喀斯特洼地表层土壤水分的空间异质性及其尺度效应[J]. 土壤学报, 2008,45(3):544-549. ZHANG Jiguang, CHEN Hongsong, SU Yirong, et al. Spatial variability of soil moisture in surface layer in depressed Karst region and its scale effect[J]. Acta pedologica sinica, 2008,45(3):544-549.(in Chinese)[5]LARK R M, RAWLINS B G, ROBINSON D A, et al. Implications of short-range spatial variation of soil bulk density for adequate field-sampling protocols: methodology and results from two contrasting soils[J]. European journal of soil science, 2014,65(6):803-814.[6]王军,傅伯杰,邱扬,等. 黄土丘陵小流域土壤水分的时空变异特征——半变异函数[J]. 地理学报,2000,55(4):428-438. WANG Jun, FU Bojie, Qiu Yang, et al. Spatiotemporal variability of soil moisture in small catchment on Loess Plateau—semivariograms[J]. Acta geographica sinica, 2000,55(4):428-438.(in Chinese)[7]SHE Dongli, SHAO Ming′an. Spatial variability of soil organic C and total N in a small catchment of the Loess Plateau, China[J]. Acta agriculturae scandinavica, Section B-soil and plant science, 2009,59:514-524.[8]HE Y, HU K L, HUANG Y F, et al. Analysis of the anisotropic spatial variability and three-dimensional computer simulation of agricultural soil bulk density in an alluvial plain of north China[J]. Mathematical and computer modelling, 2010,51(11/12):1351-1356.[9]姚荣江, 杨劲松, 刘广明. 黄河三角洲地区土壤容重空间变异性分析[J]. 灌溉排水学报,2006, 25(4): 11-15. YAO Rongjiang, YANG Jinsong, LIU Guangming. Spatial variability of soil bulk density in the Yellow River Delta[J]. Journal of irrigation and drainage, 2006,25(4):11-15.(in Chinese)[10]佘冬立,邵明安,俞双恩. 黄土高原水蚀风蚀交错带小流域土壤矿质氮空间变异性[J]. 农业工程学报,2010,26(6):89-96. SHE Dongli, SHAO Ming′an, YU Shuang′en. Spatial variability of soil mineral nitrogen in a small catchment in the wind-water erosion crisscross zone of Loess Plateau[J]. Transactions of the CSAE, 2010,26(6):89-96.(in Chinese)[11]BLOSCHL G, SIVAPALAN M. Scale issues in hydrological modeling: a review [J]. Hydrological processes, 1995,9:251-290.[12]WESTERN A W, GRAYSON R B, BLOSCHL G, et al. Observed spatial organization of soil moisture and its relation to terrain indices[J]. Water resources research, 1999,35(3):797-810.
