An assessment of some soil properties using geostatistics methods in Lampungchu sub-watershed, Northeastern, Thailand

Abstract

This study aimed to assessing some top soil properties in Lampungchu sub watershed. Results
from soil laboratory such as electronic conductivity (Ec), organic matter (OM) extractable calcium (Ca),
extractable magnesium (Mg), extractable sodium (Na) and sodium absorption ratio (SAR) were analyzed
using descriptive statistics and geo-statistics, then produced spatial distribute maps of soil properties of
the study area.
The results found that, electric conductivity in the study area ranged from 0.01 to 180 decisiemens
per meter, organic matter content ranged from 0.60 to 1.64 g kg-1, extractable calcium ranged from 0.21 to 416.67 cmol kg-1, extractable magnesium ranged from 0.09 to 39.17 cmol kg-1, extractable sodium
ranged from 0.08 to 934.13 cmol kg-1 and sodium absorption ratio ranged from 0.11 to 147.57. Every soil
properties had high spatial dependence and varied. Semivariogram analysis shown that, the suitable
variogram for electronic conductivity was Spherical, for organic matter was Gaussian, for extractable
calcium was Circular, for extractable magnesium was Spherical, extractable sodium were Gaussian and
Stable, and for sodium absorption ratio were Exponential.
The soil properties spatial distribution maps shown that, there was high value of electronic
conductivity, extractable calcium, extractable magnesium and extractable sodium in the south of study
area. There was high value of organic matter in the middle of study area and there was high value ranged
from middle to north of the study area.