Relationship between soil electrical conductivity of 1:5 soil suspension and saturation extract
1997
Nidchaporn Narapong
Experiment on relationship between soil electrical conductivity of 1:5 suspension (EC1:5) and saturation extract (ECe) was conducted to find out any correction term(s) that could convert EC1:5 into ECe. Five postulated correction terms under studied were: 1) K1, derived from a ratio of water used in extraction of salts from soil sample of certian extraction method in association with a ratio of all salt compounds extracted by a particular measurement method; 2) K2, derived from a ratio of water used in extraction of salts from soil sample of certian extraction method in association with a ratio of slightly soluble salt and soluble salt based on total salt quantity of EC1:5 method; 3) K3 similar to K2 except the ratio of extracted salts was restricted to quantity of salt to be dissolved out as of each extraction method; 4) K4, derived from a ratio of water used in extraction only; 5) K5 was a "b" regression coefficient of the regression equation of Existing ECe on Existing EC1:5. Soil samples in this study were collected from 16 soil series of 41 locations complied of 67 samples, stratified into soil group of low CaSO4 content, high CaSO4 content with 10 percent, 10-20 percent, 20-35 percent, 35 percent clay content. Existing EC1:5 and Existing ECe of all soil samples were measured and Estimated ECe were computed from various correction terms. Evaluation of Estimated ECe was based on regression-correlation analysis and analysis of variance (Dunnett test). The result of this experiment revealed that only the correction term K5 had a trend to be a suitable correction term in converting EC1:5 into ECe. But it was not valid to be applied to general soil samples since the K5 was the "b" regression coefficient of the regression equation of Existing ECe on Existing EC1:5 (of these soil samples of this experiment). Thus, there was none correction term to convert EC1:5 into ECe for general soil samples.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Kasetsart University