红壤区土壤有机碳时间变异及合理采样点数量研究  

Temporal Variability of Soil Organic Carbon and Rational Sample Size in Red Soil Region

作　　者：张忠启[1] 于法展[1] 于东升[2] 胡丹[1] 

机构地区：[1]江苏师范大学城市与环境学院,江苏徐州221116 [2]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008

出　　处：《土壤学报》2016年第4期891-900,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41201213;41571206);土壤与农业可持续发展国家重点实验室开放基金项目(0812201231);中国科学院战略性先导科技专项项目(XDA05050507)资助;~~

摘　　要：相对于土壤有机碳(soil organic carbon,SOC)空间变异性及合理采样点数量的研究,其时间变异性及揭示特定时段SOC变化所需采样点数量的研究较少。选择红壤丘陵区的江西省余江县为研究区,分析了1982—2007年SOC含量的时间变异特征,并估算了揭示该时段SOC变化所需土壤采样点数量。结果表明,1982—2007年SOC含量均值由14.18增至16.27 g kg-1,增幅为14.74%,其变异系数则由0.22上升为0.44。各土地利用方式中,水田和林地SOC含量分别增加了2.93和3.12g kg-1,而旱地则降低了2.55 g kg-1;同时各利用方式的SOC含量变异系数均出现较大幅度的提高。基于两时段的全部样点,在95%和90%置信区间上,计算得到揭示该时段全县SOC时间变异所需的采样点数量分别为186和147。基于各土地利用方式的SOC变化,计算得到水田、旱地和林地所需采样点数量分别为68、44和144(95%置信区间)及54、34和112(90%置信区间);揭示旱地SOC变化所需采样点数量应为水田的60%以上,而林地所需样点则为水田的2倍以上。该研究结果可为红壤区SOC时间变异性及其调查采样提供参考。【Objective】The knowledge about characteristics of the temporal variation of soil organic carbon（SOC）over a region and a rational sample size needed for expositing the temporal variation is of important significance to the study to reveal tendency of the temporal variation of SOC in a region efficiently and evaluate regional agricultural management practices. So far much has been done on spatial variability of SOC in a region and its rational sample size,while little has been reported on temporal variability of SOC and rational sample size needed to reveal SOC variability in a given time period. 【Method】To make up the shortage,Yujiang County of Jiangxi Province was selected as study area,and the data of soil sample size in 1982 and 2007 as basis,and then spatial distribution maps of SOC in 1982 and 2007 were plotted by means of Kriging. Through raster overlay operation of the two SOC content maps,characteristics of the temporal variation of SOC content during the period of 1982-2007 were worked out and then used as basis to estimate the number of sampling sites needed to exposit that variation. 【Result】Results show that the mean SOC content in 1982-2007 increased by from 14.18 to 16.27 g kg-1 with a growth rate of 14.74%,while its coefficient of variation（CV）rose from 0.22 to 0.44,both demonstrating a large growth. However,SOC content varied with land-use. Among the three main patterns of land-use,paddy fields and forest lands experienced rising in SOC from 15.10 to 18.02 and from 12.63 to 15.75 g kg-1 or by 19.34% and 24.70%,respectively,during the period of 1982-2007,whereas uplands did oppositely in SOC content,decreasing from 11.62 to 9.07,or by 21.94%. However,in the meantime,the three patterns all had a drastic increase in CV of SOC content. In the light of spatial distribution of the variation of SOC content,the northern and southwestern parts of Yujiang County were on a substantially increasing trend,while the central-eastern part was on a declining trend,which was closely related to sp

关 键 词：土壤有机碳 时间变异 采样点数量 红壤丘陵区 

分 类 号：S159.2[农业科学—土壤学]