Microbial competition and soil structure limit the expression of allelochemicals in nature

摘要: In this chapter we review the literature on the fate of allelochemicals in soil with special emphasis on the microbial mineralization of such compounds by soil microorganisms. It is our thesis that most purported alleochemicals could not build up to phytotoxic levels under natural conditions. Recent literature indicates that even in the absence of microbial metabolism, soil renders compounds much less toxic than they are in laboratory solutions. This lessened toxicity is due to slowed diffusion rates in soil and to various complexation and sorptive reactions (discussed below and by Huang et al., this volume). Added to these abiotic checks on toxicity is the potential for microbial destruction of allelochemicals in soil. Most soil microbes are carbon limited and many soil organisms can very rapidly mineralize aromatic compounds. On a per weight basis, aromatic compounds are more energy rich than simple sugars and thus …