Spatial variability assessment of soil nutrients i

Authors: Yongcun Zhao Xianghua Xu Jeremy Landon Darilek Biao Huang Weixia Sun Xuezheng Shi

Publish Date: 2008/06/05

Volume: 57, Issue: 5, Pages: 1089-1102

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Abstract

Topsoil samples 0–20 cm n = 237 were collected from Rugao County China Geostatistical variogram analysis sequential Gaussian simulation SGS and principal component PC analysis were applied to assess spatial variability of soil nutrients identify the possible areas of nutrient deficiency and explore spatial scale of variability of soil nutrients in the county High variability of soil nutrient such as soil organic matter SOM total nitrogen TN available P K Fe Mn Cu Zn and B concentrations were observed Soil nutrient properties displayed significant differences in their spatial structures with available Cu having strong spatial dependence SOM and available P having weak spatial dependence and other nutrient properties having moderate spatial dependence The soil nutrient deficiency defined here as measured nutrient concentrations which do not meet the advisory threshold values specific to the county for dominant crops namely rice wheat and rape seeds was observed in available K and Zn and the deficient areas covered 38 and 11 respectively The first three PCs of the nine soil nutrient properties explained 6240 of the total variance TN and SOM with higher loadings on PC1 are closely related to soil texture derived from different parent materials The PC2 combined intermediate response variables such as available Zn and P that are likely to be controlled by land use and soil pH Available B has the highest loading on PC3 and its variability of concentrations may be primarily ascribed to localized anthropogenic influence The amelioration of soil physical properties ie soil texture and soil pH may improve the availability of soil nutrients and the sustainability of the agricultural system of Rugao CountyFunding provided by the Knowledge Innovation Program of the Chinese Academy of Sciences ISSASIP0604 KZCX2YW409 Natural Science Foundation of Jiangsu Province BK2006581 and the State Key Laboratory of Soil and Sustainable Agriculture 0751010000 We gratefully thank the anonymous reviewers for their constructive and valuable advices for the paper We also especially thank Dr Pierre Goovaerts for his help in providing reprints of the related papers

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