Pedosphere 27(2): 338--343, 2017
ISSN 1002-0160/CN 32-1315/P
©2017 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Application of ordinary kriging in mapping soil organic carbon in Zambia
Lydia Mumbi CHABALA1, Augustine MULOLWA2,Obed LUNGU1
1Department of Soil Science, University of Zambia, School of Agricultural Sciences, P.O. Box 32379, Lusaka (Zambia)
2 Department of Geomatic Engineering, University of Zambia, School of Engineering/National Remote Sensing Center, P.O. Box 32379, Lusaka (Zambia)
Corresponding Author:lchabala@unza.zm.
ABSTRACT
      The quantification of the pattern and spatial distribution of soil organic carbon (SOC) is fundamental to understand many ecosystem processes.This study aimed to apply ordinary kriging (OK) to model the spatial distribution of SOC in a selected part of Zambia.A total of 100 soil samples were collected from the study area and analyzed for SOC by determining soil oxidizable carbon using the Walkley-Black method.An automated fitting procedure was followed when modeling the spatial structure of the SOC data with the exponential semivariogram. The results indicated that the short range spatial dependence of SOC was strong with a nugget close to zero.The spatial autocorrelation was high to medium with a nugget to sill ratio of 0.25.The root mean square error of the predictions was 0.64, which represented 58.18% of the mean observed data for SOC. It can be concluded that the generated map could serve as a proxy for SOC in the region where evidence of spatial structure and quantitative estimates of uncertainty are reported. Therefore, the maps produced can be used as guides for various uses including optimization of soil sampling.
Key Words:  exponential semivariogram, geographical distribution, geostatistical procedure, oxidizable carbon, spatial autocorrelation
Citation: Mumbi, C., Augustine, M. and Obed, L. 2017. Application of ordinary kriging in mapping soil organic carbon in Zambia. Pedosphere. 27(2): 338-343.
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