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土壤属性变异性的幅度效应研究对土壤数字制图、土壤调查及农业生产均具有重要意义。针对江西东乡县研究区域水田—中潴灰鳝泥田(土种)一种土地利用与土壤的复合类型单元,设定了8个土壤采样幅度研究区,并利用多层次嵌套布点方法在每个采样幅度区分别布设60个采样点,共采集337个样点的土壤表层(0~20cm)样品;运用多种函数拟合分析手段,揭示单种复合类型单元(水田—中潴灰鳝泥田)土壤全氮、全磷、全钾含量的空间变异性随采样幅度的变化特征。结果表明,土壤全量元素的空间变异性均具有明显的幅度效应特征,全氮、全磷、全钾含量的变异系数均随采样幅度的拓展而逐渐增加,而增加趋势则逐渐变缓。不同土壤全量元素空间变异性体现出不同的幅度效应特征,土壤全氮、全磷变异系数(%)的幅度效应刻画函数为CV=b×Da(R2>0.87,p<0.001),土壤全钾为CV=e(a/D+b)(R2>0.93,p<0.001),D为幅度表征指标(km);不同土壤全量元素变异系数随采样幅度快速与缓慢变化的幅度分界点位置存在明显差异,表明基于复合类型单元的土壤多属性调查采样布点与分析策略需要统筹考虑。研究结果对于红壤丘陵区县域土壤调查样点合理布设具有重要的启示和参考价值。
The study of amplitude effect of soil attribute variability is of great significance to digital mapping of soil, soil investigation and agricultural production. According to the compound type unit of land use and soil in muddy field (soil type) of paddy field-soil pool in the research area of Dongxiang County, Jiangxi Province, eight soil sampling amplitude study areas were set up and multilevel nested arrangement method was used in each A total of 337 samples of soil surface (0 ~ 20cm) samples were collected from a total of 60 sampling points in the sampling amplitude region. Using a variety of function fitting analysis methods, a single composite type unit (paddy field - Spatial variability of soil total nitrogen, total phosphorus and total potassium content with sampling amplitude changes. The results showed that the spatial variability of soil total elements had obvious amplitude effect characteristics. The coefficients of variation of total nitrogen, total phosphorus and total potassium all increased with the expansion of sampling amplitudes, while the increasing trend gradually became slower. The spatial variability of total elements in different soils showed different amplitude effect characteristics. The amplitude effect of total and total phosphorus coefficient of variation (%) was CV = b × Da (R2> 0.87, p <0.001) (R2> 0.93, p <0.001), and D is the index of amplitude characterization (km). The significant difference of the coefficient of variation between different soil total elements with the rapid and slow sampling amplitude The results show that the multi-attribute soil sampling based on compound type unit needs to take overall consideration of sampling distribution and analysis strategy. The research results have important enlightenment and reference value for the reasonable layout of soil survey sample in red soil hilly region.