Abstract

Fractions of selenium present in the soil profiles of three Swedish podzols were analysed using a sequential extraction scheme to characterize Se distribution among the organic and inorganic fractions. The process by which selenite deposited from the atmosphere is retained in a podzolic profile rich in organic matter was studied in a column experiment. Selenium present in organic fractions accounted for most of the Se extracted by Na4P2O7/NaOH. All soil organic matter fractions, particularly those in the B horizons, were considerably enriched with Se as compared with plant biomass. The most enriched fraction was that containing hydrophobic fulvates which had C to Se ratios ranging from 33 000 to 80 000. The distribution of Se among the organic fractions differed markedly from that of sulphur.Selenite applied to columns continuously for 67 d was fixed very rapidly upon entering the forest floor layers, with 77% being recovered in the top 2 cm of the forest floor after the experiment. In column leachates from the surface layers, C to Se ratios decreased progressively following Se application. No effect specifically related to Se application was observed for leachates and soil horizons underlying Bs1. The mechanism responsible for the efficient and rapid Se immobilization by organic matter is unknown.

Published in

Journal Of Soil Sciences
1992, Volume: 43, number: 3, pages: 461-472
Publisher: BLACKWELL SCIENCE LTD

SLU Authors

• Johnsson, Lars E.

  • Department of Soil Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Soil Science


Publication identifier

DOI: https://doi.org/10.1111/j.1365-2389.1992.tb00152.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/69512