1. Effects of soil organic matter on pH-dependent phosphate sorption by soils
- Author
-
Natsuyo Uchida and Syuntaro Hiradate
- Subjects
Bicarbonate ,Soil organic matter ,Inorganic chemistry ,Soil Science ,Soil classification ,Sorption ,Plant Science ,Andisol ,Phosphate ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Soil water ,Hydrogen peroxide - Abstract
Effects of soil organic matter (80M) on P sorption of soils still remain to be clarified because contradictory results have been reported in the literature. In the present study, pH-dependent P sorption on an allophanic Andisol and an alluvial soil was compared with that on hydrogen peroxide (H202)-treated, acid-oxalate (OX)-treated, and dithionite-citrate- bicarbonate (DCB)-treated soils. Removal of 80M increased or decreased P sorption depending on the equilibrium pH values and soil types. In the H2O2 OX-, and DCB-treated soils, P sorption was pH-dependent, but this trend was not conspicuous in the untreated soils. It is likely that 80M affects P sorption of soils through three factors, competitive sorption, inhibition of polymerization and crystallization of metals such as AI and Fe, and flexible structure of metal-80M complexes. As a result, the number of available sites for P sorption would remain relatively constant in the wide range of equilibrium pH values in the presence of 80M. The P so...
- Published
- 2004