›› 2019, Vol. 31 ›› Issue (1): 139-148.DOI: 10.3969/j.issn.1004-1524.2019.01.18

• Environmental Science • Previous Articles     Next Articles

Spatial heterogeneity of available potassium in topsoil based on co-Kriging

JIANG Yefeng, GUO Xi*   

  1. Key Laboratory of Poyang Lake Watershed Agricultural Resources and Ecology of Jiangxi Province, Jiangxi Agricultural University, Nanchang 330045, China
  • Received:2018-03-21 Online:2019-01-25 Published:2019-04-09

Abstract: The spatial heterogeneity of soil available potassium (AK) was quantified by using general statistics combined with geostatistics based on soil data collected from field surveys (0-20 cm) in the formula fertilization project in Wannian County. The results showed that soil AK ranged from 33.46 mg·kg-1 to 164.84 mg·kg-1 with an average of 82.04 mg·kg-1 in the study area, and was in the fourth grade (classification standard of soil nutrients in the second soil surveys) with a coefficient variation of 30.49%. Parent materials, soil group (subgroup and soil family), elevation, pH, and cation exchange capacity (CEC) had significant (P<0.01) effects on the spatial variation of soil AK. The results of cross-validation showed that co-Kriging with auxiliary variables could improve accuracy compared to ordinary Kriging, the more auxiliary variables, the higher the simulation accuracy, and the more detailed spatial heterogeneity description. The spatial distribution map of soil AK could offer scientific basis for local soil AK management and precision agriculture.

Key words: available potassium, spatial heterogeneity, Wannian County, co-Kriging

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