摘要
分别以10cm×10cm和2m×2m的网格对潮土（底锈干润雏形土）地区两块面积为1m×1m（1号区）（砂壤土）和30m×18m（2号区）（壤质黏土）的两块样区进行采样，研究其土壤重金属有效性的空间变异。结果表明。DTPA提取态Cu、Zn、Pb、Mn含量变异系数在22．4％，75．9％之间：1号区各元素含量平均值和变异系数均大于2号区对应元素：1号区Zn变异系数最大。地统计学分析表明。4种重金属有效态含量在1号区的块金值和基底效应均小于2号区。其中以2号区Pb的数值最大、Mn次之。两种尺度下。Pb都是4种元素中空间分布受随机性因素影响最大的元素：重金属有效性的空间分布均表现出等值线与作物种植行近似平行的现象。尤其以Pb、Cu和Mn最为明显。以上结果表明，2m×2m的网格更有利于反映潮土重金属有效性的空间变异受人为因素的影响，潮土重金属有效性的空间变异还受到土壤质地、耕作活动、元素类型等因素的影响。
Two plots in Fluvo-aquic soil （Endorusti-Ustic Cambosols） region were sampled with different grids sizes, Plot 1 （sandy loam, 1 m × 1 m） with grid size of 10 cm × 10 cm and Plot 2 （loamy clay, 30 m× 18 m） with grid size of 2 m × 2 m. Soil samples were extracted with DTPA and analyzed with flame atomic absorption spectrometry for Cu, Zn, Pb and Mn contents. Results indicated that variation coefficients （CV） of 4 elements ranged from 0.224 to 0.759. Mean contents and CV of 4 elements in Plot 1 were all higher than those in Plot 2, with Zn having maximum CV in Plot 1. Geostatistic results showed that all 4 elements had higher values of nugget and nugget/sill in Plot 1 than in Plot 2 and Pb of Plot 2 had maximum values, followed by Mn. Pb was affected most by random factors in both plots. Most isoline parts were approximately parallel with crop rows in both plots, especially Pb, Cu and Mn. It suggested that sampling grid size of 2 m × 2 m was better in indicating effect of random factors on spatial distribution of heavy metals than 10 cm × 10 cm in Fluvo-aquic soil region. Spatial distribution of heavy metals in Fluvo-aquic soil was also affected by soil texture, tilth activity, element type, and other land management practice.
出处
《土壤》
CAS
CSCD
北大核心
2006年第6期782-789,共8页
Soils
关键词
潮土
重金属
有效性
空间变异性
小尺度
Fluvo-aquic soil, Heavy metal, Availability, Spatial distribution, Small scale
