Fungal toxicity of mobilized soil aluminum and manganese.

Inhibition of Aspergillus flavus growth from spores was used as a simple bioassay for toxicity of Al and Mn mobilized by simulated acid precipitation. Al was identified as being toxic in soil leachates resulting from acid inputs of pH less than 2.7. Inhibition by Mn was not detectable. The addition of fluoride significantly reduced Al toxicity, suggesting that biotoxicity of Al is partially dependent on the anionic composition of the soil solution.