The interaction of atmospheric and soil sulfur on the sulfur and selenium concentration of range plants

Abstract

A native northern mixed prairie, Montana, U.S.A., was exposed to three controlled levels of sulfur dioxide and subplots fertilized with sulfur and/or selenium. Plant species that accumulated relatively greater quantities of soil sulfur did not necessarily accumulate relatively greater quantities of atmospheric sulfur, andvisa versa. Plant-sulfur concentrations increased with increasing time and level of exposure, but the rate of increase in plant-sulfur concentrations decreased with increasing SO2 concentration. Plants exposed to the high-SO2 concentration tended to have lower sulfur concentrations when growing in the sulfur-or the selenium-fertilized plots. High soil selenium caused a reduction in plant-sulfur content, but a decrease in plant selenium concentration with high soil sulfur could be detected only when comparing plants on the selenium and sulfur plus selenium plots, where high plant selenium concentrations were encountered.