基于协同克里格的橡胶园土壤速效钾空间变异性  

Spatial variability of soil available potassium in rubber plantation based on coKriging

作　　者：冯家东 吴炳孙[2] 王晶晶[1] FENG Jia-dong;WU Bing-sun;WANG Jing-jing(College of Forestry,Hainan University,Haikou 570228,China;Rubber Research Institute,Chinese Aaddemy of Tropical Agricultural Sciences,Haikou 571101,China)

机构地区：[1]海南大学林学院,海口570228 [2]中国热带农业科学院橡胶研究所,海口571101

出　　处：《应用生态学报》2022年第4期915-921,共7页Chinese Journal of Applied Ecology

基　　金：中国热带农业科学院基本科研业务费专项基金(1630022017008);海南省自然科学基金高层次人才项目(320RC486)资助。

摘　　要：选取有效变量的协同克里格方法能够提高县域尺度橡胶园土壤速效钾的空间预测精度,对橡胶树精准施肥管理具有重要意义。本研究以海南省白沙县橡胶园0~20 cm耕层土壤为对象,采用地统计学分析土壤速效钾的空间变异特征,运用相关分析筛选显著的特征变量,并比较不同变量的协同克里格(COK)空间插值精度。结果表明:研究区土壤速效钾平均含量为44.65 g·kg^(-1),总体处于缺乏状态;变异系数为52.6%,属中等变异强度;块金效应为12.5%,存在较强的空间自相关。有机质、高程与土壤速效钾含量关系密切,均呈极显著相关;有机质(COK_(2))、高程(COK_(3))、有机质+高程(COK_(1))3种协变量的COK空间插值预测精度均高于普通克里格法(OK),交叉验证模型拟合精度为COK_(1)>COK_(2)> COK_(3)>OK拟合精度与协变量选取的数量不呈正比,选取相关性更高的协变量更有利于反映区域土壤属性的空间异质性。研究区土壤速效钾含量具有西北部较高、中偏东部地区较低的分布特点。研究结果为今后开展橡胶园土壤钾素管理提供了理论依据。The coKriging method of selecting effective variables is helpful to improve the spatial prediction accuracy of soil available potassium in county-scale rubber plantation, which is of significance in precision fertilization management of rubber plantation. In this study, we analyzed the spatial variability characteristics of soil available potassium in 0-20 cm layer in the rubber plantation of Baisha County, Hainan Province, by geostatistics. The significant characteristic variables were screened by correlation analysis, and the spatial interpolation precisions of coKriging(COK) of different variables were compared. The results showed that the average soil available potassium content in the study area was 44.65 g·kg^(-1), generally at a state of shortage. The variable coefficient was 52.6%, which was a moderate intensity of variation. The nugget effect was 12.5%, with a strong spatial autocorrelation. The organic matter and elevation were closely related to soil available potassium content. The COK spatial interpolation prediction precisions of the three covariates of organic matter(COK_(1)), elevation(COK_(2)), and organic matter+elevation(COK_(3)) were all higher than ordinary Kriging(OK), and the fitting precision of the cross-validation model was COK_(1)>COK_(2)>COK_(3)>OK. The fitting precision was not proportional to the number of covariates selected. Selecting more correlated covariates was more conducive to reflecting the spatial heterogeneity of soil properties. The soil available potassium content was higher in the northwest and lower in the central and eastern regions, which provided a theoretical basis for the further development of soil potassium management in rubber plantations.

关 键 词：土壤速效钾 协同克里格 协变量 空间变异 

分 类 号：S794.1[农业科学—林木遗传育种] S714[农业科学—林学]