Contribution of Parker and Product indexes to evaluate weathering condition of Yellow Brown Forest soils in Japan

• Published in: Geoderma Vol. 130; no. 3; pp. 346 - 355
• Main Authors: Souri, B., Watanabe, M., Sakagami, K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2006; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Earth sciences; Earth, ocean, space; Exact sciences and technology; Forests; Fundamental and applied biological sciences. Psychology; high temperature; Japan; Parker index; Physicochemical properties; Product index; Q1; Q3; Soil; Soil color; Soil weathering; Soils; Surficial geology; weathering; Far East; Japan; Soil color; Product index; Parker index; Soil weathering; physical weathering; color; Lateral; silica; chemical properties; Psychometrics; weathering; Index; samples; high temperature; Standards; coordination; physicochemical properties; rocks; Brown forest soils; Asia; Ratio; soils
• ISSN: 0016-7061; 1872-6259
• DOI: 10.1016/j.geoderma.2005.02.007

Soil weathering is recognizable through study on physico-chemical characteristics of soil. In this study, Parker, ([(Na)
a
/
0.35]
+
[(Mg)
a
/
0.9]
+
[(K)
a
/
0.25]
+
[(Ca)
a
/
0.7])
×
100, and Product, [SiO
2
/
(TiO
2
+
Fe
2O
3
+
SiO
2
+
Al
2O
3)]
×
100, weathering indexes, originally developed for study on rocks, were tested on Yellow Brown Forest soils from two different regions in Japan. The results showed that the contribution of the mentioned indexes can be used for study on soils weathering. In other word, in a two-dimensional coordination system where the axes are Parker and Product indexes, regarding to the chemical bases of the indexes, initial and lateral products of weathering can be tracked at the same time.
Additionally, the indexes relations with soil color were studied after exposing the samples at a high temperature. Remarkable relationships between
a*
/
b* ratio–parameters of psychometric chromaticness of color in CIE color standard system–and these two weathering indexes demonstrated that
a*
/
b* ratio can be applied reliably to estimate the quantities of Parker and Product indexes in Yellow Brown Forest soils.