12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Long-Term Change in the Biogeochemical Cycling ...
View graph of relations

« Back

Long-Term Change in the Biogeochemical Cycling of Atmospheric Selenium: Deposition to Plants and Soil.

Research output: Contribution to journalJournal article

Published

Journal publication date1993
JournalJournal of Geophysical Research: Atmospheres
Journal numberD9
Volume98
Number of pages8
Pages16769-16776
Original languageEnglish

Abstract

Retrospective analysis of archived soil and herbage samples from Rothamsted Experimental Station, southeast England, has determined the long-term changes in selenium deposition over the last century. Three out of four soils (those under permanent grassland, or growing wheat and barley) accumulated Se at a rate of circa 0.15% yr−1 (rate based on Se concentration, normalized to the earliest date circa 100 years earlier), with a net flux in the order 60–90 μg m−2 yr−1. The increase in soil growing root crops was smaller, with an increase of only 0.07% yr−1, possibly reflecting larger volatilization losses from this soil. Herbage samples were sensitive to changes in air composition. In the earlier half of the twentieth century there was an increase in the selenium content of herbage, probably from increased atmospheric deposition following increased use of fossil fuels. However, following the Clean Air Act (1956) the atmospheric loading of Se at this UK site appears to have declined, with contemporary Se concentrations in herbage considerably lower than they were in the 1970s, probably reflecting a change in fossil fuel usage from coal to oil and gas. The atmosphere has been a significant source of Se to plants and therefore grazing livestock. If the decline in the atmospheric input of selenium to herbage continues, selenium deficiency in livestock may become more prevalent in areas where soil concentrations are marginal.