CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Soil Research   
Soil Research
Journal Banner
  Soil, land care and environmental research
blank image Search
blank image blank image
blank image
  Advanced Search

Journal Home
About the Journal
Editorial Structure
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Virtual Issues
Sample Issue
For Authors
General Information
Submit Article
Author Instructions
Open Access
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter logo LinkedIn

Now Online

Land Resources Surveys


Article     |     Next >>   Contents Vol 45(3)

Characteristics and genesis of two strongly weathered soils in Samar, Philippines

Ian A. Navarrete A C, Victor B. Asio A D, Reinhold Jahn B, Kiyoshi Tsutsuki C

A Department of Agronomy and Soil Science, Leyte State University, Baybay, Leyte 6521-A, Philippines.
B Institute of Soil Science and Plant Nutrition, Martin-Luther University Halle-Wittenberg, Weidenplan 14, D-06108 Halle (Saale), Germany.
C Laboratory of Environmental Soil Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho 080-8555, Japan.
D Corresponding author. Email: vbasio_ph@yahoo.com
PDF (1.3 MB) $25
 Export Citation


Very limited data have been published on the nature of strongly weathered soils in geologically young humid tropical islands. The study evaluated the characteristics and formation of 2 strongly weathered soils in the island of Samar, Philippines, one developed from slate (Bagacay soil) and the other from ultrabasic rock (Salcedo soil). Results revealed that the soils have generally similar morphological characteristics, particularly in terms of colour (2.5 YR-10 R), solum thickness (>5.0 m), and structure (granular to subangular blocky), although the Salcedo soil has much higher clay content than the Bagacay soil. Both soils have similar chemical properties (e.g. acidic, low exchangeable bases) except that the Salcedo soil has lower CEC values but higher exchangeable Na content, resulting in a higher base saturation. They also have high dithionite-extractable Fe contents and very low oxalate/dithionite ratios and are dominated by halloysite, kaolinite, gibbsite, goethite, hematite, and quartz in the clay fraction. Apparently as a result of its more weatherable ultrabasic parent rock and more stable geomorphic surface, the Salcedo soil shows more advanced weathering and soil development than the Bagacay soil. Salcedo soil is classified as Haplic Ferralsol (Dystric, Clayic, Rhodic) in the World Reference Base or very fine, sesquic, isohyperthermic, Rhodic Hapludox in the Soil Taxonomy. Bagacay soil is a Haplic Acrisol (Alumic, Hyperdystric, Clayic, Rhodic) or fine, kaolinitic, isohyperthermic, Typic Paleudult. The Salcedo soil has very high Ni and Cr contents inherited from its ultrabasic parent material. The study reveals that on the geologically young humid tropical island of Samar, the characteristics and genesis of strongly weathered soils are greatly affected by the geochemical characteristic of the parent rock material.

Keywords: Oxisols, Ultisols, tropical island soils, ultrabasic rocks, slate.

Subscriber Login

Legal & Privacy | Contact Us | Help


© CSIRO 1996-2016