The movement and distribution of manganese added to soil

Abstract

Autoradiography was used to trace the movement and distribution of divalent manganese (Mn) labelled with 54Mn after addition to samples of two whole soils and to the natural aggregates of one of the soils. Various treatments involving waterlogging, incubation at 100 cm suction and air-drying were imposed. Given time, irrespective of the treatment, the 54Mn tended to accumulate at spots of varying size inside the aggregates and throughout the whole-soil samples. Since divalent Mn added to the two soils is converted rapidly to easily reducible forms by a process inhibited by microbial poisons, the spots represent presumably centres where the divalent Mn is oxidized microbially to insoluble oxides of Mn.