Technical ArticlesSOIL SOLUTION COMPOSITION, WATER TABLES, AND REDOX POTENTIALS OF ANTHRAQUIC ULTISOLS IN A TOPOSEQUENCEHseu, Zeng-Yei; Chen, Zueng-Sang; Leu, Ing-YihAuthor Information Graduate Institute of Agricultural Chemistry, National Taiwan University, Taipei 106-17, Taiwan, ROC. Dr. Chen is corresponding author. E-mail: [email protected] Received Oct 21, 1999; accepted June 5, 2000. Soil Science: November 2000 - Volume 165 - Issue 11 - p 869-880 Buy Abstract This study examines the relationship of soil solution composition, water table, and redox potential (Eh) in three rice-growing Ultisols of the Chungli Terrace toposequence in northern Taiwan. The three soil series were Houhu (Typic Plinthaquult), Hsinwu (Typic Plinthaquult), and Lungchung (Plinthaquic Paleudult). Water tables and redox potentials were monitored in 1996 and 1997. Soil solutions were collected in 1997 at different depths by the tension free method. Redoximorphic features were consistently found in the Btv horizons of the three pedons. Sodium, calcium, and sulfate were the dominant ions in soil solutions at different depths. Decreased concentrations of Na, Mg, Mn, and Cl were associated with increasing elevation in this toposequence, and this trend was then related to the soil moisture regime and the distance from the sea. There was much more Mn than Fe in the soil solution. The low concentration of Fe in the soil solution was the result of low Fe activity ratio (Fe0/Fed) associated with low organic carbon content in the soils; it was also caused by dilution of the irrigation water utilized for rice production. Manganese is more highly correlated than Fe with the concentration in the soil solution and the redox regime. © 2000 Lippincott Williams & Wilkins, Inc.