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Profile characterization of some alfisols and ultisols in Thailand / Suraphol Ratanasophon.

By:

Ratanasophon, Suraphol [author]

Contributor(s):

Nontecillo, Lune A [adviser]

Material type: Text

TextLanguage: English Publication details: Los Baños, Laguna, 1981. Cavite State University- Main Campus,Description: 218 pages : illustrations ; 28 cmContent type:

text

Media type:

unmediated

Carrier type:

volume

Subject(s):

DDC classification:

631.4 R18 1981

Online resources:

Click here to view thesis abstract and table of contents

Abstract: SURAPHOL RATANASOPHON, University of the Philippines at Los Banos, February, 1981. Profile Characterization of some alfisols and Ultisols in Thailand. Major Professor: Pr. Lune A. Nontecillo Some physical, chemical, mineralogical and surface charge characteristics of four Alfisols and four Ultisols profiles fr in Nakhon Ratchasima province, Thailand, were studied in an attempt to understand more the distinguishing characteristics of Alfisols and Ultisols and to determine the role of a number of these properties in soil classification. Ultisols showed finer texture and higher water retentions but less available water holding capacity and bulk density than Alfisols. The increase in percent clay with depth that met criterion for argillic horizons indicated their fairly well developed profiled, The application of the Pigeon equation worked out better on Ultisols than on Alfisols in estimating soil moisture content at field capacity and at permanent wilting point based on percent silt, clay and organic matter. There were more organic matter, available phosphorus and potassium, free iron, exchangeable aluminium and percent aluminium saturation in Ultisols than in Alfisols. The electrical conductivity values of all soil samples were lower than 4m mho/em, indicating no adverse salinity effect on plants in these soils. Ultisols were generally more acidic than Alfisols. Aluminum saturation of 30% in subsoils within the critical pH range of 5.4 to 5.1 was proposed as the tentative new criterion for the maximum limit of Alfisols and minimum limit of Ultisols to differentiate one from the other. Using effective cation exchange capacity (ECEC) as a more realistic cation exchange capacity (CHC) measurement for routine analysis was confirmed. Direct measurement of apparent cation exchange capacity (ACEC) of clay was also recommended. Base saturation (BS) of 50% of CHG obtained by ammonium acetate method and 65% BS of BCEC were suggested as the alternating criteria instead of 35% BS of GES obtained by sur of exchangeable cations in the present classification of Alfisols and Ultisols. Clay weathering index as an indicator of the soil order categories worked better in Ultisols than in Alfisols. The higher degree of pe-~ Gogenic development with more predominating pH-dependent (PDC) of Ultisols than Alfisols was indicated by the greater values of zero point of charge (ZPC), PDC and the ratios of PNG to the permanent charge (PC). With increasing pedogenic development the ZPC approached the pH measured in FCl of the soils. This was also shown by some decreases in the relative differences of PC, FCEC/SCEC ratios and net permanent negative charges (6%) between Alfisols and Ultisols. All soil samples exhibited net permanent negative charges as indicated by the negative values of apH (pl measured in N KCl-pH measured in water) and Gi. The overall results showed that ZPC, PNC/PC ratio and Si may be used as the surface charge parameters for soil classification according to Soil Taxonomy (1975).

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Holdings ( 1 )
Title notes ( 4 )

Holdings
Item type	Current library	Collection	Call number	Materials specified	URL	Status	Notes	Date due	Barcode
Theses / Manuscripts	Ladislao N. Diwa Memorial Library Theses Section	Non-fiction	631.4 R18 1981 (Browse shelf(Opens below))		Link to resource	Room use only	T-1428		00002311

Thesis (Ph.D. - - Soil Science) University of the Philippines, College, Laguna.

Includes bibliographical references.

SURAPHOL RATANASOPHON, University of the Philippines at Los Banos, February, 1981. Profile Characterization of some alfisols and Ultisols in Thailand. Major Professor: Pr. Lune A. Nontecillo

Some physical, chemical, mineralogical and surface charge characteristics of four Alfisols and four Ultisols profiles fr in Nakhon Ratchasima province, Thailand, were studied in an attempt to understand more the distinguishing characteristics of Alfisols and Ultisols and to determine the role of a number of these properties in soil classification.

Ultisols showed finer texture and higher water retentions but less available water holding capacity and bulk density than Alfisols. The increase in percent clay with depth that met criterion for argillic horizons indicated their fairly well developed profiled, The application of the Pigeon equation worked out

better on Ultisols than on Alfisols in estimating soil moisture content at field capacity and at permanent wilting point based on percent silt, clay and organic matter.

There were more organic matter, available phosphorus and potassium, free iron, exchangeable aluminium and percent aluminium saturation in Ultisols than in Alfisols. The electrical conductivity values of all soil samples were lower than 4m mho/em, indicating no adverse salinity effect on plants in these soils. Ultisols were generally more acidic than Alfisols.

Aluminum saturation of 30% in subsoils within the critical pH range of 5.4 to 5.1 was proposed as the tentative new criterion for the maximum limit of Alfisols and minimum limit of Ultisols to differentiate one from the other.

Using effective cation exchange capacity (ECEC) as a more realistic cation exchange capacity (CHC) measurement for routine analysis was confirmed. Direct measurement of apparent cation exchange capacity (ACEC) of clay was also recommended. Base saturation (BS) of 50% of CHG obtained by ammonium acetate method and 65% BS of BCEC were suggested as the alternating criteria instead of 35% BS of GES obtained by sur of exchangeable cations in the present classification
of Alfisols and Ultisols. Clay weathering index as an indicator of the soil order categories worked better in Ultisols than in Alfisols. The higher degree of pe-~
Gogenic development with more predominating pH-dependent (PDC) of Ultisols than Alfisols was indicated by the greater values of zero point of charge (ZPC), PDC and the ratios of PNG to the permanent charge (PC).

With increasing pedogenic development the ZPC approached the pH measured in FCl of the soils. This was also shown by some decreases in the relative differences of PC, FCEC/SCEC ratios and net permanent negative charges (6%) between Alfisols and Ultisols. All soil samples exhibited net permanent negative charges as indicated by the negative values of apH (pl measured in N KCl-pH measured in water) and Gi. The overall results showed that ZPC, PNC/PC ratio and Si may be used as the surface charge parameters for soil classification according to Soil Taxonomy (1975).

Submitted to the University Library 01/07/1994 T-1428