VARIATIONS IN ANNUAL PRECIPITATION AND SELENIUM ACCUMULATION BY MILK-VETCH

Four Se accumulators and two non-accumulator plants were examined for their Se content in wet and dry years. No significant change in Se quantity was noted in the non-accumulators in relation to variations in annual precipitation. However, the concentration of Se found in accumulator plants is significantly higher in wet years than in dry ones. Furthermore, in wet years there is a higher percentage of water soluble Se in these plants than in dry ones. The soils supporting these plants were also examined for their Se content. In dry years these soils contain more water soluble Se than in wet ones but, in dry years, this form of Se is less available due to the lack of available moisture. High precipitation may tend to reduce absorption of Se by plants by diluting the water soluble Se present in the soil solution, but it is clear that it also promotes absorption of Se by encouraging vigorous growth of these accumulator plants. © 1979, Taylor & Francis Group, LLC. All rights reserved.