松嫩平原苏打盐渍化旱田土壤表观电导率空间变异

发布时间：2018-05-12 18:03

本文选题：土壤表观电导率 + 空间变异　；参考：《生态学报》2017年04期

【摘要】：在松嫩平原西部吉林省大安市乐胜乡,于2013年4月20日选择盐碱程度不均一的典型盐渍化旱田地块,面积为4.8 hm~2作为研究样地。利用EM38大地电导率仪测定结合田间定点采样,并通过经典统计和地统计相结合的方法研究了盐渍化旱田土壤表观电导率空间变异特征,分析了土壤表观电导率与土壤盐碱指标之间的关系。结果表明,盐渍化旱田土壤水平方向表观电导率(EC_h)经对数转换后具有强空间自相关,其变异特征主要是与地形地貌和水文状况等结构性因素有关。垂直方向表观电导率(EC_v)经对数转换后具有中等空间自相关性,其变异特征受结构性因素和随机因素共同作用。EC_h和EC_v半方差模拟的最优模型分别为球状模型和指数模型。Pearson分析表明土壤表观电导率(EC_h和EC_v)与土壤盐碱指标EC_(1∶5)、pH_(1∶5)、SAR、SC、Na~+、CO_3~(2-)、HCO_3~-呈正相关关系(P0.05),EC_h与土壤盐碱指标相关系数均大于EC_v。在实际应用中可以用EC_h来指示土壤的盐碱程度。回归分析表明土壤表观电导率(EC_h和EC_v)与土壤盐碱指标呈线性相关,且EC_h回归模型的决定系数均大于EC_v回归模型的决定系数,可用水平方向土壤表观电导率(EC_h)来计算土壤盐碱指标,进行土壤盐渍化的快速评估。
[Abstract]:In Lesheng Township, Da'an City, Jilin Province in the western part of Songnen Plain, on April 20, 2013, typical salinized dryland plots with uneven salinity were selected, with an area of 4.8 hm~2. The spatial variation characteristics of soil apparent conductivity in salinized arid fields were studied by means of EM38 geoconductivity measurement combined with field fixed-point sampling and the combination of classical statistics and geostatistics. The relationship between soil apparent conductivity and soil saline-alkali index was analyzed. The results showed that the apparent electrical conductivity of soil in horizontal direction was strongly spatial autocorrelation after logarithmic transformation, and its variation was mainly related to the structural factors such as topography and hydrology. Vertical apparent conductivity (ECV) has moderate spatial autocorrelation after logarithmic transformation. The optimum models for the semi-variance simulation of ECs and EC_v are spherical model and exponential model respectively. Pearson analysis shows that the apparent conductivity of soil is higher than that of ECS, and that of soil salinity index ECS is 1: 5 and pH ~ (-1) ~ (-1), respectively, and that of soil saline-alkali index is 1: 5 / 5 ~ + pH ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1). A positive correlation was found between the correlation coefficient of P0.05 and soil saline-alkali index and the correlation coefficient between the correlation coefficient and the soil saline-alkali index. In practical application, EC_h can be used to indicate the salinity of soil. The results of regression analysis showed that the apparent conductivity of soil was linearly correlated with soil saline-alkali index, and the determination coefficient of EC_h regression model was higher than that of EC_v regression model. The soil salinization index can be calculated by using the horizontal apparent electrical conductivity (ECH), and the soil salinization can be evaluated quickly.
【作者单位】：中国科学院东北地理与农业生态研究所;
【基金】：国家重点基础研究发展计划资助项目(2015CB150802) 国家重点研发计划资助项目(2016YFC0501200) 国家自然科学基金资助项目(41071022,41571210)
【分类号】：S156.41

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