Fundamentals for Improving Phosphorus Cycle in Soil-Plant Systems

Poster Presentatio

Introduction to Studies on Volcanic Ash Soils in Japan and International Collaboration

Original Pape

Aluminum Dynamics in Nonallophanic Andosols from Northeastern Japan

We studied Al dynamics in nonallophanic Andosols from northeastern Japan by determination of Al solubility and Al release rates, selective dissolution analyses of active Al fractions, and examination of liming effect on the active Al. Aluminum solubility of the nonallophanic Andosols was lower than that of gibbsite in the lower pH range and showed oversaturation in the higher pH range, indicating that the Al solubility was controlled by Al-humus complexes. There was a close relationship between Al saturation (KCl-extractable Al/effective CEC) and the amount of pyrophosphate extractable Al, indicating that exchangeable Al is equilibrated with organically complexed Al. Liming (CaCO_3 treatment) largely reduced the amount of organically complexed Al (pyrophosphate- and CuCl_2-extractable Al), confirming that a portion of Al-humus complexes are labile

Changes in Elemental Composition with Andosolization

A total of 57 elements in volcanic ash soils from 18 pedons distributed in Japan were analyzed and the relationships between noncrystalline material content and that of individual elements were examined. The content of the noncrystalline materials was estimated by using acid-oxalate extraction. Oxalate-extractable Fe (Fe_o) and Al (Al_o) corresponds to Fe in ferrihydrite and Al in allophane-imogolite plus Al complexed with humus, respectively. Silicon and alkaline or alkaline-earth elements such as Na, K. Ca, and Sr tended to decrease during the process of volcanic ash soil formation, i.e., andosolization. In contrast, the contents of Al, Y and the first transition metals tended to increase with the increasing content of noncrystalline materials. The first transition metals showed a high correlation with Feo suggesting their similarity in chemical behavior during andosolization. The lanthanoid elements tended to increase with the increasing Al_o and Fe_o content

Inorganic Constituents in Soil

This open access book is a must-read for students of and beginners in soil science. In a well-organized and easy-to-follow manner, it provides basic outlines of soil minerals, new methods and recent developments in the field, with a special focus on visual aids. The chapters on primary minerals, secondary minerals, non-crystalline inorganic constituents and inorganic constituents sensitive to varying redox conditions will help readers understand the basic components of soils. Further, readers are introduced to new analytical methods with the aid of microscopy and recent developments in the field. Uniquely, the book features case studies on the identification and isolation methods for vivianite crystals from paddy field soils, as well as a useful procedure for identifying noncrystalline constituents such as volcanic glasses and plant opals, which can also be applied to other soils depending on the local conditions. Given its focus and coverage, the book will be useful to all readers who are interested in agronomy, plant production science, agricultural chemistry and environmental science. In addition, it can help biogeochemists further expand their research work on the rhizosphere of wetland plant roots, iron and phosphate dynamics, etc

Phosphates in the Air-dried Residues of Water or Dilute Acid Extracts from Compost

Poster Sessio

Use of Soil Database for Pedological Research as Exemplified by Volcanic Ash Soils

Original Pape

Factors Affecting Organic Carbon Accumulation in Humus Horizons of Andosols from the Tohoku University World Andosol Database

Poster Sessio