Effect of Reduction Associated with Organic Matter Decomposition on Magnetic Properties of Red Soils  

作　　者：DONGRUIBIN ZHANGWEIGUO LUSHENGGAO YULIZHONG YUJINYAN 

机构地区：[1]DepartmentofEnvironmentalengineering,NanchangUniversity,Nanchang330029(China) [2]StateKeyLaboratoryofEstuarine&CoastalResearch,EastChinaNormalUniversity,Shanghai200062(China) [3]CollegeofEnvironmentalandResourceSciences,zhejiangUniversity,Hangzhou310029(China)

出　　处：《Pedosphere》2003年第2期103-110,共8页土壤圈（英文版）

摘　　要：Five soils derived from different parent materials were sampled from red soilregion of southern China and studied by magnetic methodology to understand to what extent ironreduction would affect soil magnetic properties and how iron reduction would affect the magneticminerals in soils. Reduction associated with organic matter decomposition strongly affected soilmagnetic parameters at low pH. The losses of original soil magnetic signals in terms of magneticsusceptibility (X), 'Soft' isothermal remanent magnetization ('Soft' IRM), anhysteretic remanentmagnetization (ARM) and saturation isothermal remanent magnetization (SIRM) at pH 4～6 during thetwo-month saturation treatment, were 66%～94%, 54%～90%, 64%～95% and 33%～83%, respectively. Thesechanges were interpreted as a consequence of substantial dissolution of maghaemite and haematite inthe soils. At pH 10, however, there was no significant magnetic change observed. Moreover, stablesingle domain soil maghaemite grains were also sensitive to reduction, which suggested that bothpedogenic and detrital maghaemite were not stable in acid and reducing environments. Goethite,instead, was the most stable iron form under reducing conditions.Five soils derived from different parent materials were sampled from red soil region of southern China and studied by magnetic methodology to understand to what extent iron reduction would affect soil magnetic properties and how iron reduction would affect the magnetic minerals in soils. Reduction associated with organic matter decomposition strongly affected soil magnetic parameters at low pH. The losses of orition (SIRM) at pH 4～6 during the two-month saturation treatment, were 66%～94%, 54%～90%, 64%～95% and 33%～83%, respectively. These changes were interpreted as a consequence of substantial dissolution of maghaemite and haematite in the soils. At pH 10, however, there was no significant magnetic change observed. Moreover, stable single domain soil maghaemite grains were also sensitive to reduction, which suggested that both pedogenic and detrital maghaemite were not stable in acid and reducing environments.Goethite, instead, was the most stable iron form under reducing conditions.

关 键 词：GOETHITE HAEMATITE maghaemite magnetic susceptibility REDUCTION 

分 类 号：S153.62[农业科学—土壤学]