PERSISTENCE OF ISOFLAVONES FORMONONETIN AND BIOCHANIN-A IN SOIL AND THEIR EFFECTS ON SOIL MICROBE POPULATIONS

Persistence of the isoflavones formononetin and biochanin A in soil wa s investigated by HPLC analysis. Biochanin A disappeared more rapidly than formononetin in nonsterile soil. In soil planted with corn seedli ngs, the disappearance was dramamtic for both isoflavones. The results suggested that soil microbial populations were able to metabolize the se isoflavones. The response of several microbial populations to isofl avone amendments was measured in soil samples obtained from Michigan p otato fields. Results suggested that the isoflavones formononetin and biochanin A were able to stimulate the growth of soil microorganisms.